EXHIBIT 99.1

   Semitool Names Larry Murphy as Executive Vice President and COO;
  Appoints Steve Stahlberg to Board of Directors and Audit Committee

    KALISPELL, Mont.--(BUSINESS WIRE)--April 27, 2004--Semitool(R),
Inc. (Nasdaq: SMTL), a leading supplier of wafer surface preparation
and electrochemical deposition systems, today announced that it has
named Larry Murphy executive vice president and chief operating
officer, effective May 24, 2004. The company also announced the
appointment of Steve Stahlberg to the company's board of directors and
audit committee, filling a vacancy on that committee.
    Ray Thompson, Semitool's president and chief executive officer
said, "Larry brings to Semitool an in-depth understanding of our
business and customers. We are enthusiastic to have him on our team.
Larry will work side-by-side as my partner, seeking to position our
company to meet the expanding opportunities we have as a result of our
new products and the needs of this particular upturn in the
semiconductor industry. In addition, Larry's extensive experience and
knowledge of the Asian markets will be invaluable as we approach more
aggressively the opportunities throughout Asia, which represent the
fastest growing areas of demand for semiconductor equipment."
    Murphy joins Semitool after 15 years with Tosoh SMD, Inc., a U.S.
subsidiary of Tosoh Corporation headquartered in Tokyo, Japan. Murphy
was Tosoh SMD's president and chief executive officer, as well as
chairman of their Taiwanese, Korean and Singapore subsidiaries.
Previously at Tosoh SMD, Murphy held several executive positions of
increasing responsibility, including chief operating officer, vice
president of sales and marketing and global sales manager.
    Murphy holds a bachelor of science degree in geophysics and
geology from Michigan State University and a masters of business
administration from the Kellogg School of Management at Northwestern
University. Murphy is also a board member of the Center for
Excellence in Manufacturing Management at The Ohio State University.
    Turning to the Stahlberg appointment, Thompson commented: "We are
delighted to have Steve Stahlberg join our board. He adds strength to
our audit committee, given his extensive experience in business
oversight, and will aid us as we expand the role of that committee to
meet the requirements of Sarbanes-Oxley."
    Stahlberg, a certified public accountant, is a founder of
Stahlberg & Sutherland, which specializes in management advisory
services, cash flow analysis and forecasting, and employee relations.
Prior to forming the firm, he worked extensively in governmental and
nonprofit auditing as well as management advisory services. Stahlberg
holds a bachelor of science degree in business administration with
honors, with an emphasis in accounting, from the University of
Montana. He is a member of the Montana Society of Certified Public
Accountants and its local chapter and is a member of the honorary
accounting fraternity, Beta Alpha Psi.

    About Semitool, Inc.

    Semitool is a worldwide leader in the design, development,
manufacture, and support of high- performance, multi-chamber
single-wafer and batch wet chemical processing systems for use 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 the Nasdaq National Market 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.

    CONTACT: Semitool, Inc.
             Larry Viano, Chief Financial Officer, 406/752-2107
             lviano@semitool.com
               or
             Investor Relations Partners, Inc.
             Joanne Barbieri, 973/535-8389
             joanneb@irpartners.com