For more information, contact:

Jim Donaldson Advanced Energy Industries, Inc. 970.407.6374Marna Shillman

Marna Shillman Advanced Energy Industries, Inc. 970.407.6280 marna.shillman@aei.com

Ft Collins, Colorado (September 22, 1999) – Advanced Energy Industries, Inc. (Nasdaq NM: AEIS) has named Chris Fergen Vice President and General Manager of AE's Tower Electronics Division located in Fridley, Minnesota. Mr. Fergen will have direct responsibility for Tower's overall performance. His initial focus will be to expand Tower's product markets and increase sales. In announcing the new appointment, Hollis Caswell, AE’s President and COO, said, “Chris has a strong background in business development and customer relations. I am confident that Chris and his organization will capitalize on Tower's market opportunities to expand our business.”

Mr. Fergen joined AE in May of 1997. Most recently, he was Director of the Semiconductor Business Unit. Before that, he was the Director of the Applied Materials Business Unit. Prior to joining AE, he worked at Motorola in Austin, Texas, and Johnson Matthey Electronics in San Diego, California.

Tower Electronics, Inc. was founded in 1978 and acquired by AE in August of 1997. Tower designs and manufacturers product power supplies for such diverse applications as night-vision systems, medical instrumentation, computer peripherals, networking systems, telecommunications, and others.

Advanced Energy is a worldwide leader in the development and marketing of critical power conversion and control system solutions. Customers throughout the world use Advanced Energy’s products where thin film deposition and etch are critical steps in their manufacturing processes. These include the manufacture of semiconductors, CD-ROMs, DVDs, compact disks, flat panel displays, disk drives, optical and architectural glass. In addition, Advanced Energy provides the process power solutions of choice to a growing number of industrial and commercial applications in the automotive, food packaging and tool industries. Founded in 1981, AE is a publicly held company traded on Nasdaq under the symbol AEIS.