Semitool Provides Update on Anticipated Fourth Quarter 2007 Financial Results

KALISPELL, MT--(Marketwire - October 23, 2007) - Semitool, Inc. (NASDAQ: SMTL), a leading manufacturer of wafer processing equipment for the semiconductor industry, today provided a preliminary overview of its anticipated financial results for the fourth quarter ended September 30, 2007. Fourth quarter bookings were $60.2 million, representing a 20% improvement over the prior period and the strongest quarterly bookings performance of fiscal 2007.

The company expects to report fourth quarter revenue of $47 million, which is within management's previous guidance range of $45 million to $48 million. Including the impact of an inventory write off of $3 million, or approximately $0.06 per share, the company expects to report a fourth quarter loss per share of between $0.05 and $0.07. Semitool said the write off is related to recent product enhancements, which have led to inventory obsolescence. Final fourth quarter financial results are subject to completion of the company's annual audit, and will be reported after the market closes on November 9, 2007.

Larry Murphy, president and chief operating officer, said, "Our strong fourth quarter bookings are evidence of the success we have had expanding our customer base and capturing new process-of-record opportunities, particularly for emerging applications such as single wafer front-end-of-line cleaning and copper damascene for memory. As our customers transition from technology to capacity buys, we have seen a marked increase in sales of our production-related tools. Based on recent customer feedback, we are optimistic this trend will continue over the next fiscal year."

About Semitool, Inc.

Semitool designs, manufactures and supports highly engineered, multi-chamber single-wafer and batch wet chemical processing equipment used in the fabrication of semiconductor devices. The company's primary suites of equipment include electrochemical deposition systems for electroplating copper, gold, solder and other metals; surface preparation systems for cleaning, stripping and etching silicon wafers; and wafer transport container cleaning systems. The company's equipment is used in semiconductor fabrication front-end and back-end processes, including wafer level packaging.

Headquartered in Kalispell, Montana, Semitool maintains sales and support centers in the United States, Europe and Asia. The company's stock trades on Nasdaq under the symbol SMTL. For more information, please visit the company's website at www.semitool.com.

Semitool is a registered trademark of Semitool, Inc.

Safe Harbor Statement

This news release contains forward-looking statements, including (i) preliminary estimates of revenue and earnings per share for the fourth quarter of fiscal 2007 and (ii) statements related to the trend in increased sales of production-related tools continuing over the next fiscal year. The Company will release comprehensive consolidated financial results in its fourth quarter news release and conference call expected to occur on November 9, 2007. The forward-looking statements included in this release are based on management's assumptions and estimates as of the date hereof and are subject to risks and uncertainties that are discussed in our filings with the U.S. Securities and Exchange Commission, including our Annual Report on Form 10-K for the fiscal year ended September 30, 2006 and subsequent filings. In addition, bookings are not necessarily an indication of revenue in any future financial period. Many factors can adversely affect future financial performance, including cancellations and push-backs, unanticipated manufacturing and delivery considerations, customers' on-site acceptance of our products, unanticipated costs, as well as a number of other risk factors described in our Annual Report on Form 10-K. Our business in general is subject to risks that can cause actual results to differ materially from those anticipated in our forward-looking statements, including, without limitation, demand being adversely affected by the cyclicality in the semiconductor industry, delays in acceptance and payment for shipped tools, the company's ability to timely deliver and support its products, technological changes that affect our ability to compete, the risks associated with competing on a global basis and possible volatility in key markets such as Asia. We assume no obligation to update forward-looking statements that become untrue because of subsequent events.

Contact Information: Contacts: Semitool, Inc. Larry Viano Chief Financial Officer 406.752.2107 Pfeiffer High Investor Relations, Inc. Geoff High 303.393.7044 www.pfeifferhigh.com