Exhibit 99.1

FOR IMMEDIATE RELEASE

KLA-TENCOR REPORTS FISCAL 2010 FOURTH QUARTER AND FULL YEAR RESULTS

MILPITAS, Calif., July 29, 2010—KLA-Tencor Corporation^® (NASDAQ: KLAC) today announced operating results for its fourth quarter and fiscal year ended June 30, 2010. KLA-Tencor reported GAAP net income of $113 million and GAAP earnings per diluted share of $0.66 on revenues of $559 million for the fourth quarter of fiscal year 2010. For the year ended June 30, 2010, the company reported GAAP net income of $212 million and GAAP earnings per diluted share of $1.23 on revenues of $1.8 billion.

“Robust product demand in each of our major end markets, geographies and product offerings, coupled with solid execution by the KLA-Tencor team resulted in strong financial results in the fourth quarter,” said Rick Wallace, KLA-Tencor’s president and chief executive officer. “These results reflect our team’s commitment to helping customers solve complex yield challenges at the leading edge, as well as KLA-Tencor’s ability to execute against our strategic objectives in order to maintain our market and technology leadership.”

GAAP Results

Non-GAAP Results

A reconciliation between GAAP operating results and non-GAAP operating results is provided following the financial statements that are part of this release. Non-GAAP results include the impact of stock-based compensation, but exclude the impact of acquisition, restatement and restructuring related items, goodwill and intangible asset impairment, and certain discrete tax items.

KLA-Tencor will discuss the results for its fiscal year 2010 fourth quarter and full year, along with its outlook, on a conference call today beginning at 2:00 p.m. Pacific Daylight Time. A webcast of the call will be available at: www.kla-tencor.com

Forward-Looking Statements:

Statements in this press release other than historical facts, such as statements regarding KLA-Tencor’s position as a market and technology leader and the company’s ability to successfully innovate, develop and sell new technologies and products that meet customer needs, are forward-looking statements and are subject to the Safe Harbor provisions created by the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based on current information and expectations, and involve a number of risks and uncertainties. Actual results may differ materially from those projected in such statements due to various factors, including but not limited to: the demand for semiconductors; the financial condition of the global capital markets and the general macroeconomic environment; new and enhanced product and technology offerings by competitors; cancellation of orders by customers; the ability of KLA-Tencor’s research and development teams to successfully innovate and develop technologies and products that are responsive to customer demands; KLA-Tencor’s ability to successfully integrate and manage businesses that it acquires; market acceptance of the company’s existing and newly issued products; and changing customer demands. For other factors that may cause actual results to differ materially from those projected and anticipated in forward-looking statements in this release, please refer to KLA-Tencor’s Annual Report on Form 10-K for the year ended June 30, 2009, subsequently filed Quarterly Reports on Form 10-Q and other filings with the Securities and Exchange Commission (including, but not limited to, the risk factors described therein). KLA-Tencor assumes no obligation to, and does not currently intend to, update these forward-looking statements.

About KLA-Tencor:

KLA-Tencor Corporation (NASDAQ: KLAC), a leading provider of process control and yield management solutions, partners with customers around the world to develop state-of-the-art inspection and metrology technologies. These technologies serve the semiconductor, data storage, LED, photovoltaic, and other related nanoelectronics industries. With a portfolio of industry-standard products and a team of world-class engineers and scientists, the company has created superior solutions for its customers for over 30 years. Headquartered in Milpitas, California, KLA-Tencor has dedicated customer operations and service centers around the world. Additional information may be found at www.kla-tencor.com. (KLAC-F)

Use of Non-GAAP Financial Information:

The non-GAAP and supplemental information provided in this press release is a supplement to, and not a substitute for, KLA-Tencor’s financial results presented in accordance with United States GAAP.

To supplement KLA-Tencor’s condensed consolidated financial statements presented in accordance with GAAP, the company provides certain non-GAAP financial information, which is adjusted from results based on GAAP to exclude certain costs and expenses, as well as other supplemental information. The non-GAAP and supplemental information is provided to enhance the user’s overall understanding of KLA-Tencor’s operating performance and its prospects in the future. Specifically, KLA-Tencor believes that the non-GAAP information provides useful measures to both management and investors regarding financial and business trends relating to KLA-Tencor’s financial performance by excluding certain costs and expenses that the company believes are not indicative of its core operating results. The non-GAAP information is among the budgeting and planning tools that management uses for future forecasting. However, because there are no standardized or generally accepted definitions for most non-GAAP financial metrics, definitions of non-GAAP financial metrics (for example, determining which costs and expenses to exclude when calculating such a metric) are inherently subject to significant discretion. As a result, non-GAAP financial metrics may be defined very differently from company to company, or even from period to period within the same company, which can potentially limit the usefulness of such information to an investor. The presentation of non-GAAP and supplemental information is not meant to be considered in isolation or as a substitute for results prepared and presented in accordance with United States GAAP.

KLA-Tencor Corporation

Condensed Consolidated Unaudited Balance Sheets

KLA-Tencor Corporation

Condensed Consolidated Unaudited Statements of Operations

KLA-Tencor Corporation

Condensed Consolidated Unaudited Statements of Cash Flows

KLA-Tencor Corporation

Condensed Consolidated Unaudited Supplemental Information

(In thousands, except per share data)

Reconciliation of GAAP Net Income (Loss) to Non-GAAP Net Income (Loss)

Pre-tax impact of items included in Condensed Consolidated Unaudited Statements of Operations

To supplement our condensed consolidated financial statements presented in accordance with GAAP, we provide certain non-GAAP financial information, which is adjusted from results based on GAAP to exclude certain costs and expenses, as well as other supplemental information. The non-GAAP and supplemental information is provided to enhance the user’s overall understanding of our operating performance and our prospects in the future. Specifically, we believe that the non-GAAP information provides useful measures to both management and investors regarding financial and business trends relating to our financial performance by excluding certain costs and expenses that we believe are not indicative of our core operating results. The non-GAAP information is among the budgeting and planning tools that management uses for future forecasting. However, because there are no standardized or generally accepted definitions for most non-GAAP financial metrics, definitions of non-GAAP financial metrics (for example, determining which costs and expenses to exclude when calculating such a metric) are inherently subject to significant discretion. As a result, non-GAAP financial metrics may be defined very differently from company to company, or even from period to period within the same company, which can potentially limit the usefulness of such information to an investor. The presentation of non-GAAP and supplemental information is not meant to be considered in isolation or as a substitute for results prepared and presented in accordance with United States GAAP.