For more information, contact:

Richard Beck Advanced Energy Industries, Inc. (970) 407-6204

Janet Nelson (analysts/investors) The Financial Relations Board/BSMG WorldWide (415) 986-1591

Fort Collins, Colorado (December 9, 1999) --Advanced Energy Industries, Inc. (Nasdaq NM) AEIS today announced that it received an initial order from Hewlett Packard for power conversion products to power very high performance microprocessors. Advanced Energy also received a development contract from Hewlett Packard to continue work on other advanced technology power conversion products.

“This area of technology is an extension of our in-depth knowledge of radio frequency power conversion systems and provides high current at very low voltages to meet the requirements of future microprocessors and ASICs” said Richard Scholl, Chief Technology Officer for Advanced Energy. “Our power systems design is at the leading edge of technology and the products are designed to meet the stringent requirements for power and space in the workstations under development by HP” continued Scholl.

“We are pleased to have been chosen by Hewlett Packard as the company to meet their demanding requirements for these systems, “ said Douglas Schatz , Chief Executive Officer of Advanced Energy. “This area of technology is part of our strategy to be the leading designer and manufacturer of power conversion systems for technically challenging, high performance applications” continued Schatz.

“This technology will permit Hewlett Packard to power the microprocessors of the future,” said Sam Babb, Director of Power Supply Development of the HP Fort Collins Workstation Group. “As our microprocessor voltages drop and power increases, the current low frequency technology simply cannot deal with the power supply issues involved.”

Safe Harbor Statement
Except for any historical information contained herein, the matter discussed in this news release are forward-looking statements that reflect our current beliefs and expectations including the achievement of goals established by the Company and continued sales growth in non-semiconductor areas. The Company continues to be susceptible to fluctuations in quarterly and annual revenues and operating results and the volatility of the semiconductor and semiconductor capital equipment industries. The Company assumes no obligation to update the information in this release.

About the Company
Founded in 1981, Advanced Energy Industries, Inc. is a leading manufacturer of power delivery systems that are critical in the manufacturing of semiconductors, data storage media, flat panel displays, and other products using thin-film technology. The Company also manufactures ion beam sources and plasma abatement systems for applications in data storage and semiconductor manufacturing. Within its comprehensive product portfolio of direct current (DC), low/mid-frequency and radio frequency (RF)solutions, the Company sells hundreds of different products critical in applications ranging from compact disks, digital video disks, flat panel displays, the most popular logic semiconductor devices, among other applications. The Company’s stock is traded on the Nasdaq National Market under the symbol AEIS.

For more information, access Advanced Energy’s web site at www.advanced-energy.com or for information via fax, no cost, dial 1-800-PRO-INFO, codes AEIS.