Exhibit 99.1

Teradyne Reports First Quarter 2010 Results

NORTH READING, Mass. – April 21, 2010 – Teradyne, Inc. (NYSE: TER) reported revenue of $330 million for the first quarter of 2010 of which $290 million was in Semiconductor Test and $40 million in Systems Test Group. On a non-GAAP basis, Teradyne’s net income in the first quarter was $61.3 million, or $0.33 per diluted share, which excluded acquired intangible asset amortization, non-cash convertible debt interest and restructuring and other charges. GAAP net income for the first quarter was $50.1 million, or $0.24 per diluted share.

Bookings in the first quarter of 2010 were $534 million of which $460 million were in Semiconductor Test and $74 million in the Systems Test Group.

Guidance for the second quarter of 2010 is revenue of $390 million to $420 million, with non-GAAP net income per diluted share of $0.45 to $0.52 and GAAP net income per diluted share between $0.33 and $0.40. Non-GAAP guidance excludes acquired intangible asset amortization, non-cash convertible debt interest and restructuring and other charges.

“We achieved another very healthy increase in orders last quarter led by our Semiconductor Test product line,” said Mike Bradley, Teradyne president and CEO. “Our wireless, microcontroller, and power management segments continued to expand and we’re encouraged to see demand increasing in Memory and Hard Disk Drive test. With another quarter of strong top line growth, our business model in the second quarter is poised to deliver the highest profit rate in nearly ten years.”

Webcast

A webcast to discuss first quarter results, along with management’s business outlook will be held at 10 a.m. EDT, Thursday, April 22, 2010. Interested investors should access the webcast at www.teradyne.com and click on “Investors” at least five minutes before the call begins. The webcast replay will be available on www.teradyne.com. In addition, a conference call replay will be available approximately two hours after the call. The replay number in the U.S. & Canada is 800-642-1687. The replay number outside the U.S. & Canada is 706-645-9291. The pass code for both numbers is 67733268. The replay will be available via phone and web site through May 14, 2010.

Non-GAAP Results

In addition to disclosing results that are determined in accordance with GAAP, Teradyne also discloses non-GAAP results of operations that exclude certain income items and charges. These results are provided as a complement to results provided in accordance with GAAP. Non-GAAP income/(loss) from operations

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and non-GAAP net income/(loss) exclude goodwill impairment, in-process research and development, non-cash convertible debt interest, write-off of credit line debt issue costs, restructuring and other, net, fair value inventory step-up related to Nextest and Eagle Test, (losses)/gains on marketable securities and acquired intangible asset amortization, as well as applicable adjustments to profit sharing (prior to January 1, 2010) and income taxes due to these exclusions. GAAP requires that these items be included in determining income/(loss) from operations and net income/(loss). Non-GAAP income/(loss) from operations, non-GAAP net income/(loss), non-GAAP income/(loss) from operations and non-GAAP net income/(loss) as a percentage of revenue, and non-GAAP net income/(loss) per share are non-GAAP measures presented to provide meaningful supplemental information regarding Teradyne’s baseline performance before gains, losses or other charges that may not be indicative of the Company’s current core business or future outlook. These non-GAAP measures are used to make operational decisions, to determine employee compensation, to forecast future operational results, and for comparison with the Company’s business plan, historical operating results and the operating results of the Company’s competitors. Non-GAAP gross margin excludes charges related to the fair value inventory step-up recorded as part of acquisition purchase accounting. GAAP requires that this item be included in determining gross margin. Non-GAAP gross margin dollar amount and percentage are non-GAAP measures that management believes provide useful supplemental information for management and the investor. Management uses non-GAAP gross margin as a performance measure for the Company’s current core business and future outlook and for comparison with the Company’s business plan, historical gross margin results and the gross margin results of the Company’s competitors. Management believes each of these non-GAAP measures provides useful supplemental information for investors, allowing greater transparency to the information used by management in its operational decision making and in the review of the Company’s financial and operational performance, as well as facilitating meaningful comparisons of the Company’s results in the current period compared with those in prior and future periods. A reconciliation of each available GAAP to non-GAAP financial measure discussed in this press release is contained in the attached exhibits and on the Teradyne website at www.teradyne.com by clicking on “Investors” and then selecting the “GAAP to Non-GAAP Reconciliation” link. The presentation of non-GAAP measures is not meant to be considered in isolation, as a substitute for, or superior to, financial measures or information provided in accordance with GAAP.

About Teradyne

Teradyne (NYSE:TER) is the leading supplier of Automatic Test Equipment used to test complex electronics used in the consumer electronics, automotive, computing, telecommunications, and aerospace and defense industries. In 2009, Teradyne had sales of $819 million. For more information, visit www.teradyne.com. Teradyne(R) is a registered trademark of Teradyne, Inc. in the U.S. and other countries. All product names are trademarks of Teradyne, Inc. (including its subsidiaries) or their respective owners.

Safe Harbor Statement

This release contains forward-looking statements regarding future business prospects, Teradyne’s results of operations and market conditions. Such statements are based on the current assumptions and expectations of Teradyne’s management and are neither promises nor guarantees of future performance. You can identify these forward-looking statements based on the context of the statements and by the fact that they use words such as “will,” “anticipate,” “expect,” “project,” “intend,” “plan,” “believe,” “target” and

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other words and terms of similar meaning in connection with any discussion of future operating or financial performance. There can be no assurance that management’s estimates of Teradyne’s future results or other forward looking statements will be achieved. Important factors that could cause actual results to differ materially from those presently expected include: conditions affecting the markets in which Teradyne operates; decreased product demand; delays in new product introductions; lack of customer acceptance of new products; unanticipated delays in meeting product demand and delivery requirements; and other events, factors and risks disclosed in filings with the SEC, including, but not limited to, the “Risk Factors” section of Teradyne’s Annual Report on Form 10-K for the fiscal year ended December 31, 2009. The forward-looking statements provided by Teradyne in this press release represent management’s views as of the date of this release. Teradyne anticipates that subsequent events and developments may cause management’s views to change. However, while Teradyne may elect to update these forward-looking statements at some point in the future, Teradyne specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing Teradyne’s views as of any date subsequent to the date of this release.

TERADYNE, INC. REPORT FOR FIRST FISCAL QUARTER OF 2010

CONDENSED CONSOLIDATED OPERATING STATEMENTS

(In thousands, except per share amounts)

CONDENSED CONSOLIDATED BALANCE SHEETS (In thousands)

GAAP to Non-GAAP Earnings Reconciliation

(In millions, except per share amounts)

For press releases and other information of interest to investors, please visit Teradyne's homepage at http://www.teradyne.com.

Contact: Teradyne, Inc.

                Andy Blanchard 978-370-2425

                Vice President of Corporate Relations