MATTSON TECHNOLOGY UPDATES INVESTMENT COMMUNITY ON PROGRESS TOWARD SUSTAINABLE PROFITABILITY

Company Leaders Discuss Actions, Products and Strategies to Deliver Results

FREMONT, Calif.- September 23, 2004 - Mattson Technology, Inc. (NASDAQ: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors, is holding a briefing for securities analysts and investors. In the meeting, Mattson Technology President and Chief Executive Officer David L. Dutton and other management executives will provide an update on the company’s progress toward market share growth and implementation of its business model that is designed to create sustainable profitability.

Topics to be discussed at the meeting include:

• Overview of the company’s core products in Strip and RTP technologies
• Technology opportunities and challenges in 300 mm, 65 nm and beyond
• Strategies to expand customer relationships and alliances
• Operational and financial strategies that should help the company through peak and trough periods in the industry

“We will share with our audience today how Mattson is delivering results through innovation, customer relationships, financial growth and operational excellence,” said Dutton. “Our product and technology leadership has delivered gains in market share in both our core product lines this year, and we intend to secure more business wins from the world’s top semiconductor companies. We have developed a solid business model and maintain a good cash position, the foundation for further growth. Our business model--which we call the cyclically flexible enterprise, or CFE, model--has not only allowed us to become a leaner and more operationally efficient company, but also one to lead our industry as a model for resilience through industry and economic cycles. We intend to remain focused on executing to our corporate strategies and driving operational excellence throughout the organization to grow the company and build sustainable value for all of our stakeholders.”

Slides of the presentations will be available at the start of the meeting, today September 23, 2004 at 1:15 p.m. Pacific Time, under the ‘Investors’ section of Mattson’s corporate website at www.mattson.com.

About Mattson Technology, Inc.

Mattson Technology, Inc. is a leading supplier of semiconductor wafer processing equipment used in the fabrication of integrated circuits. The company’s dry strip and RTP equipment utilize innovative technology to deliver advanced processing capabilities on high-productivity platforms for the fabrication of current- and next-generation devices. Since beginning operations in 1989, the company’s core vision has been to help bring technology leadership and productivity gains to semiconductor manufacturers worldwide. 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.