MATTSON TECHOLOGY ANNOUNCES AVAILABILITY OF SECOND QUARTER 2005 EARNINGS AND WEBCAST

FREMONT, Calif.- July 1, 2005 - Mattson Technology, Inc. (NASDAQ: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors, today announced that the Company will host a conference call on Wednesday, July 20, 2005 at 5:30 p.m. Eastern Time (2:30 p.m. Pacific Time). The conference call will cover second quarter 2005 earnings and current business conditions.

The company's conference call will be simultaneously available to all interested listeners via an audio webcast on the Internet. For access, visit Mattson's website www.mattson.com under the ‘Investors' section. A replay of the conference call will be available on Mattson's website for one week following the live broadcast.

About Mattson Technology, Inc.

Mattson Technology, Inc. is the leading supplier of dry strip equipment and the second largest supplier of rapid thermal processing equipment in the global semiconductor industry. The company's strip and RTP equipment utilize innovative technology to deliver advanced processing performance and productivity gains to semiconductor manufacturers worldwide for the fabrication of current- and next-generation devices. For more information, please contact Mattson Technology, Inc., 47131 Bayside Parkway, Fremont, Calif. 94538. Telephone: (800) MATTSON/(510) 657-5900. Fax: (510) 492-5911. Internet: www.mattson.com.