For more information, contact:

Mike El-Hillow Advanced Energy Industries, Inc. 970.407.6570

Cathy Kawakami Advanced Energy Industries, Inc. 970.407.6732 cathy.kawakami@aei.com

Fort Collins, Colorado, January 4, 2005—Advanced Energy (Nasdaq: AEIS) today announced the appointment of Joseph R. Bronson, 56, to the Board of Directors. Mr. Bronson was appointed President of FormFactor, Inc. (Nasdaq: FORM) in November 2004. Prior to that, Mr. Bronson was Executive Vice President and Chief Financial Officer of Applied Materials, the world’s largest manufacturer of semiconductor capital equipment. In his 20 years at Applied, he held a number of general management leadership positions, including responsibility for the etch products group, global manufacturing, and ion implantation systems.

Doug Schatz, chairman and chief executive officer said, “We are excited that Joe will bring his incredible industry and business experience to AE as we continue our technology leadership and business transformation. I have worked closely with Joe as an executive of our largest customer and have always valued his knowledge and insight.”

Mr. Bronson also serves on the board of directors of FormFactor, Inc. and Jacobs Engineering Group, a diversified technical professional consulting firm.

About Advanced Energy
Advanced Energy is a global leader in the development and support of technologies critical to high-technology manufacturing processes used in the production of semiconductors, flat panel displays, data storage products, compact discs, digital video discs, architectural glass and other advanced product applications.

Leveraging a diverse product portfolio and technology leadership, AE creates solutions that maximize process impact, improve productivity and lower cost of ownership for its customers. This portfolio includes a comprehensive line of technology solutions in power, flow management, thermal instrumentation and plasma and ion beam sources for original equipment manufacturers (OEMs) and end-users around the world.

AE operates in regional centers in North America, Asia and Europe and offers global sales and support through direct offices, representatives and distributors. Founded in 1981, AE is a publicly held company traded on Nasdaq National Market under the symbol AEIS. More information can be found at www.advanced-energy.com