Exhibit 99.1

ON Semiconductor Reports First Quarter 2011 Results

For the first quarter of 2011, highlights include total:

PHOENIX, Ariz. – May 4, 2011 – ON Semiconductor Corporation (Nasdaq: ONNN) today announced that total revenues in the first quarter of 2011 were $870.6 million, an increase of more than 50 percent from the fourth quarter of 2010. As previously announced, the company completed its acquisition of SANYO Semiconductor on January 1, 2011. During the first quarter of 2011, the company reported GAAP net income of $74.8 million, or $0.16 per fully diluted share. The first quarter 2011 GAAP net income included net charges of $46.4 million, or $0.10 per fully diluted share, from special items. The special item details can be found in the attached schedules. During the fourth quarter of 2010, the company reported a GAAP net income of $61.0 million, or $0.14 per fully diluted share. Further information, including the unaudited results of operations for SANYO Semiconductor for the first quarter of 2011, is provided in the financial tables attached to this release.

First quarter 2011 results were negatively impacted from reduced production and increased expenses incurred as a result of the Japan earthquake and resulting tsunami. There were production disruptions but only limited physical damage to our Japanese manufacturing facilities post the March 11 Japan earthquake and tsunami. While revenue was within our original guidance provided on February 3, 2011, we currently estimate that production disruptions negatively impacted our net income approximately $10 million in the first quarter of 2011. Full stabilization and recovery of our operations in Japan is progressing well. Of ON Semiconductor’s six manufacturing facilities in Japan, five came back to full production capacity and the sixth factory is ramping towards full production.

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First quarter 2011 non-GAAP net income was $121.2 million, or $0.27 per share on a fully diluted basis, which included approximately $0.06 per share on a fully diluted basis from SANYO Semiconductor. Fourth quarter 2010 non-GAAP net income was $99.2 million, or $0.22 per share on a fully diluted basis. A reconciliation of these non-GAAP financial measures (and other non-GAAP measures used elsewhere in this release, such as non-GAAP gross margin, non-GAAP gross profit and adjusted EBITDA) to the company’s most directly comparable measures prepared in accordance with U.S. GAAP are set forth in the attached schedules and on our website at http://www.onsemi.com/.

On a mix-adjusted basis, average selling prices for historical ON Semiconductor (excluding SANYO Semiconductor) in the first quarter of 2011 were approximately flat when compared to the fourth quarter of 2010. Total company GAAP gross margin in the first quarter was 27.8 percent. Total company GAAP gross margin in the first quarter included a net charge of approximately $70.9 million, or approximately 820 basis points, from special items. Total company non-GAAP gross margin in the first quarter was 36.0 percent.

Adjusted EBITDA for the first quarter of 2011 was $167.3 million. Adjusted EBITDA for the fourth quarter of 2010 was $145.4 million.

“ON Semiconductor continued its transformation in the first quarter of 2011 with the acquisition of SANYO Semiconductor,” said Keith Jackson, ON Semiconductor president and CEO. “In January, we closed the acquisition of SANYO Semiconductor and in our first quarter of operating the business, SANYO Semiconductor positively contributed to our earnings. This transaction broadens our product portfolio, adding new capabilities from microcontrollers and custom application specific integrated solutions (ASICs) to integrated power modules and motor control devices. In addition, in February we closed the acquisition of the CMOS Image Sensor Business Unit from Cypress Semiconductor Corporation which positions ON Semiconductor as a leading supplier of ultra-high-speed CMOS image sensors.”

“While total company revenues at the mid-point of our guidance for the second quarter of 2011 are anticipated to be up slightly from the first quarter of 2011, revenues, gross profit and earnings will be negatively impacted by the supply chain disruptions, reduced production and increased expenses in Japan as result of the earthquake and tsunami.” Jackson said. “Based on our current assessment, we believe the effects of the earthquake and tsunami could negatively impact total company sales by approximately $50 million and gross profit and earnings in excess of $30 million in the second quarter of 2011. This anticipated impact is already included in our guidance below. Longer term we believe we are well positioned in Japan as the country rebuilds from the tragic events of March 11.”

SECOND QUARTER 2011 OUTLOOK

“Our second quarter 2011 outlook includes SANYO Semiconductor. Based upon product booking trends, backlog levels and estimated turns levels, we anticipate that total ON Semiconductor revenues will be approximately $860 to $900 million in the second quarter of 2011,” Jackson said. “Backlog levels for the second quarter of 2011 represent over 90 percent of our anticipated second quarter 2011 revenues. We expect that average selling prices for the second quarter of 2011 will be flat to down approximately one percent when compared to the first quarter of 2011. The non-GAAP outlook for the second quarter of 2011 includes stock-based compensation expense of approximately $14 million.”

The following table outlines ON Semiconductor’s second quarter 2011 GAAP and non-GAAP outlook.

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ON SEMICONDUCTOR Q2 2011 BUSINESS OUTLOOK

TELECONFERENCE

ON Semiconductor will host a conference call for the financial community at 5:30 a.m. Pacific Time (PDT) on May 5, 2011 to discuss this announcement and ON Semiconductor’s results for the first quarter of 2011. The company will also provide a real-time audio webcast of the teleconference on the Investor Relations page of its website at http://www.onsemi.com. The webcast replay will be available at this site approximately one hour following the live broadcast and will continue to be available for approximately 30 days following the conference call. Investors and interested parties can also access the conference call through a telephone call by dialing (888) 546-9664 (U.S./Canada) or (973) 935-8144 (International). In order to join this conference call, you will be required to provide the Conference ID Number – which is 63850124. Approximately one hour following the live broadcast, the company will provide a dial-in replay that will continue to be available through May 12, 2011. To listen to the teleconference replay, call (800) 642-1687 (U.S./Canada) or (706) 645-9291 (International). You will be required to provide the Conference ID Number – which is 63850124.

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About ON Semiconductor

ON Semiconductor (Nasdaq: ONNN) is a premier supplier of high performance, silicon solutions for energy efficient electronics. The company’s broad portfolio of power and signal management, logic, discrete and custom devices helps customers effectively solve their design challenges in automotive, communications, computing, consumer, industrial, LED lighting, medical, military/aerospace and power applications. ON Semiconductor operates a world-class, value-added supply chain and a network of manufacturing facilities, sales offices and design centers in key markets throughout North America, Europe, and the Asia Pacific regions. For more information, visit http://www.onsemi.com.

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ON Semiconductor and the ON Semiconductor logo are registered trademarks of Semiconductor Components Industries, LLC. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. Although the company references its website in this news release, information on the website is not to be incorporated herein.

This document contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical facts, included or incorporated in this document could be deemed forward-looking statements, particularly statements about the future financial performance of ON Semiconductor. These forward-looking statements are often characterized by the use of words such as “believes,” “estimates,” “expects,” “projects,” “may,” “will,” “intends,” “plans,” or “anticipates,” or by discussions of strategy, plans or intentions. All forward-looking statements in this document are made based on information available to us as of the date of this release, our current expectations, forecasts and assumptions, and involve risks, uncertainties and other factors that could cause results or events to differ materially from those expressed in the forward-looking statements. Among these factors are our revenues and operating performance, poor economic conditions and markets (including current credit and financial conditions), effects of exchange rate fluctuations, the cyclical nature of the semiconductor industry, changes in demand for our products, changes in inventories at our customers and distributors, technological and product development risks, enforcement and protection of our intellectual property rights and related risks, availability of raw materials, electricity, gas, water and other supply chain uncertainties, our ability to effectively shift production to other facilities in order to maintain supply continuity for our customers, variable demand and the aggressive pricing environment for semiconductor products, our ability to successfully manufacture in increasing volumes on a cost-effective basis and with acceptable quality for our current products, competitors’ actions including the adverse impact of competitive product announcements, pricing and gross profit pressures, loss of key customers, order cancellations or reduced bookings, changes in manufacturing yields, control of costs and expenses and realization of cost savings from restructurings and synergies, significant litigation, risks associated with decisions to expend cash reserves for various uses such as debt prepayment or acquisitions rather than to retain such cash for future needs, risks associated with acquisitions and dispositions (including from integrating and consolidating, and timely filing financial information with the Securities and Exchange Commission - for, recently acquired businesses, such as SANYO Semiconductor, and difficulties encountered in accurately predicting the future financial performance of recently acquired businesses, such as SANYO Semiconductor), risks associated with our substantial leverage and restrictive covenants in our debt agreements from time to time, risks associated with our worldwide operations including foreign employment and labor matters associated with unions and collective bargaining arrangements as well as natural disasters like the Japan earthquake and tsunami affecting our operations and finances/financials, the threat or occurrence of international armed conflict and terrorist activities both in the United States and internationally, risks and costs associated with increased and new regulation of corporate governance and disclosure standards (including pursuant to Section 404 of the Sarbanes-Oxley Act of 2002), risks related to new legal requirements and risks involving environmental or other governmental regulation. Information concerning additional factors that could cause results to differ materially from those projected in the forward-looking statements is contained in ON Semiconductor’s Annual Report on Form 10-K for the period ended December 31, 2010, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and other of our filings with the Securities and Exchange Commission. If any of these trends, risks or uncertainties actually occurs or continues, our business, financial condition or operating results could be materially adversely affected, the trading prices of our securities could decline, and investors could lose all or part of their investment. Readers are cautioned not to place undue reliance on forward-

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looking statements. These forward-looking statements should not be relied upon as representing our views as of any subsequent date and we do not undertake any obligation to update forward-looking statements to reflect events or circumstances after the date they were made.

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ON SEMICONDUCTOR CORPORATION AND SUBSIDIARIES

UNAUDITED CONSOLIDATED STATEMENT OF OPERATIONS

(in millions, except per share data)

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ON SEMICONDUCTOR CORPORATION AND SUBSIDIARIES

UNAUDITED CONSOLIDATED STATEMENT OF OPERATIONS

(in millions, except per share data)

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ON SEMICONDUCTOR CORPORATION AND SUBSIDIARIES

UNAUDITED CONSOLIDATED BALANCE SHEET

(in millions)

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ON SEMICONDUCTOR CORPORATION AND SUBSIDIARIES

UNAUDITED RECONCILIATION OF NET INCOME TO ADJUSTED EBITDA* AND

CASH PROVIDED BY OPERATING ACTIVITIES

(in millions)

* Adjusted EBITDA represents net income (loss) before interest expense, interest income, provision for income taxes, depreciation and amortization expense and special items. We use the adjusted EBITDA measure for internal managerial evaluation purposes, as a means to evaluate period-to-period comparisons and as a performance metric for the vesting/releasing of certain of our performance based equity awards, and for earning of corporate cash bonuses when applicable. Adjusted EBITDA is a non-GAAP financial measure. Regulation G and other provisions of the securities laws regulate the use of financial measures that are not prepared in accordance with generally accepted accounting principles. We believe this measure provides important supplemental information to investors. However, we do not, and you should not, rely on non-GAAP financial measures alone as measures of our performance.

We believe that non-GAAP financial measures reflect an additional way of viewing aspects of our operations that – when taken together with GAAP results and the reconciliations to corresponding GAAP financial measures that we also provide in our press releases – provide a more complete understanding of factors and trends affecting our business. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with non-GAAP financial measures used by our company or other companies, even if they have similar names.

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ON SEMICONDUCTOR CORPORATION AND SUBSIDIARIES

ANALYSIS OF GAAP VERSUS NON-GAAP DISCLOSURES

(in millions, except per share and percentage data)

Total share-based compensation expense, related to the Company’s stock options, restricted stock units, restricted stock awards and employee stock purchase plan is included below.

Non-GAAP Measures

To supplement the consolidated financial results prepared under GAAP, ON Semiconductor uses non-GAAP measures which are adjusted from the most directly comparable GAAP results to exclude items related to amortization of intangible assets, amortization of acquisition-related intangibles, expensing of appraised inventory fair market value step up, purchased in-process research and development expenses, restructuring, asset impairments and other, net, goodwill impairment charges, gains and losses on debt prepayment, non-cash interest expense, their related tax effects and certain other special items as necessary. Management does not consider these charges in evaluating the core operational activities of ON Semiconductor. Management uses these non-GAAP measures internally to make strategic decisions, forecast future results and evaluate ON Semiconductor’s current performance. Most analysts covering ON Semiconductor use the non-GAAP measures as well. Given management’s use of these non-GAAP measures, ON Semiconductor believes these measures are important to investors in understanding ON Semiconductor’s current and future operating results as seen through the eyes of management. In addition, management believes these non-GAAP measures are useful to investors in enabling them to better assess changes in ON Semiconductor’s core business across different time periods. These non-GAAP measures are not in accordance with or an alternative to GAAP financial data and may be different from non-GAAP measures used by other companies. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures, even if they have similar names.

— Non-GAAP gross profit and gross margin. The use of this non-GAAP financial measure allows management to evaluate the gross margin of the company’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including expensing of appraised inventory fair market value step up and amortization of intangible assets. In addition, it is an important component of management’s internal performance measurement and reward process as it is used to assess the current and historical financial results of the business, for strategic decision making, preparing budgets and forecasting future results. Management presents this non-GAAP financial measure to enable investors and analysts to evaluate our revenue generation performance relative to the direct costs of revenue of ON Semiconductor’s core businesses.

— Non-GAAP net income and net income per share. The use of these non-GAAP financial measures allow management to evaluate the operating results of ON Semiconductor’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including amortization of intangible assets, amortization of acquisition-related intangibles, expensing of appraised inventory fair market value step up, purchased in-process research and development expenses, restructuring, asset impairments and other, net, goodwill impairment charges, gains and losses on debt prepayment, non-cash interest expense, their related tax effects and certain other special items as necessary. In addition, they are important components of management’s internal performance measurement and reward process as they are used to assess the current and historical financial results of the business, for strategic decision making, preparing budgets and forecasting future results. Management presents these non-GAAP financial measures to enable investors and analysts to understand the results of operations of ON Semiconductor’s core businesses and to compare our results of operations on a more consistent basis against that of other companies in our industry.

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ON SEMICONDUCTOR CORPORATION AND SUBSIDIARIES

ANALYSIS OF GAAP VERSUS NON-GAAP DISCLOSURES

(in millions, except per share and percentage data)

Non-GAAP Measures

To supplement the consolidated financial results prepared under GAAP, ON Semiconductor uses non-GAAP measures which are adjusted from the most directly comparable GAAP results to exclude items related to amortization of intangible assets, amortization of acquisition-related intangibles, expensing of appraised inventory fair market value step up, purchased in-process research and development expenses, restructuring, asset impairments and other, net, goodwill impairment charges, gains and losses on debt prepayment, non-cash interest expense, their related tax effects and certain other special items as necessary. Management does not consider these charges in evaluating the core operational activities of ON Semiconductor. Management uses these non-GAAP measures internally to make strategic decisions, forecast future results and evaluate ON Semiconductor’s current performance. Most analysts covering ON Semiconductor use the non-GAAP measures as well. Given management’s use of these non-GAAP measures, ON Semiconductor believes these measures are important to investors in understanding ON Semiconductor’s current and future operating results as seen through the eyes of management. In addition, management believes these non-GAAP measures are useful to investors in enabling them to better assess changes in ON Semiconductor’s core business across different time periods. These non-GAAP measures are not in accordance with or an alternative to GAAP financial data and may be different from non-GAAP measures used by other companies. Because non-GAAP financial measures are not standardized it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures, even if they have similar names.

— Non-GAAP gross profit and gross margin. The use of this non-GAAP financial measure allows management to evaluate the gross margin of the company’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including expensing of appraised inventory fair market value step up and amortization of intangible assets. In addition, it is an important component of management’s internal performance measurement and reward process as it is used to assess the current and historical financial results of the business, for strategic decision making, preparing budgets and forecasting future results. Management presents this non-GAAP financial measure to enable investors and analysts to evaluate our revenue generation performance relative to the direct costs of revenue of ON Semiconductor’s core businesses.

— Non-GAAP net income and net income per share. The use of these non-GAAP financial measures allow management to evaluate the operating results of ON Semiconductor’s core businesses and trends across different reporting periods on a consistent basis, independent of non-cash items including amortization of intangible assets, amortization of acquisition-related intangibles, expensing of appraised inventory fair market value step up, purchased in-process research and development expenses, restructuring, asset impairments and other, net, goodwill impairment charges, gains and losses on debt prepayment, non-cash interest expense, their related tax effects and certain other special items as necessary. In addition, they are important components of management’s internal performance measurement and reward process as it is used to assess the current and historical financial results of the business, for strategic decision making, preparing budgets and forecasting future results. Management presents these non-GAAP financial measures to enable investors and analysts to understand the results of operations of ON Semiconductor’s core businesses and to compare our results of operations on a more consistent basis against that of other companies in our industry.