For more information, contact:

Mike El-Hillow Advanced Energy Industries, Inc. 970.407.6570 mike.el-hillow@aei.com

Cathy Kawakami Advanced Energy Industries, Inc. 970.407.6570 cathy.kawakami@aei.com

FORT COLLINS, Colo., July 21, 2004—Doug Schatz, chairman and chief executive officer, and Mike El-Hillow, executive vice president and chief financial officer, will be available to answer your questions regarding second quarter 2004 results tonight at 7:00 PM Eastern Time. Due to technical difficulties during the earlier conference call, several callers were prevented from accessing the conference, and all participants were prevented from asking questions.

Management's prepared remarks from the earlier call are available via archived webcast on the Company's website, www.advanced-energy.com, and also via telephone replay by dialing 800-642-1687 or 706-645-9291 and entering passcode 6231797.

To access tonight's question and answer session, please dial 888-713-4717. A telephone replay will be available by dialing 800-642-1687 or 706-645-9291 and entering passcode 8964196.

About Advanced Energy

Advanced Energy (Nasdaq: AEIS) 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, Advanced Energy 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, thermal management, and plasma and ion beam sources for original equipment manufacturers (OEMs) and end-users around the world.

Advanced Energy 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, Advanced Energy is a publicly held company traded on the Nasdaq National Market under the symbol AEIS. For more information, please visit our corporate website: www.advanced-energy.com