Exhibit 99.1

Financial News Release

CONTACTS:
Danny Herron		Annie Leschin/Vanessa Lehr
Advanced Energy Industries, Inc.		Advanced Energy Industries, Inc.
970.407.6570		970.407.6555
danny.herron@aei.com		ir@aei.com

ADVANCED ENERGY ANNOUNCES SOLID FIRST QUARTER RESULTS

	•		Revenue of $137.7 million, a 97.5% increase over Q1 2010
	•		Operating Income of $24.4 million, 17.7% of revenue
	•		EPS of $0.43 share
	•		Record bookings of $184.0 million

Fort Collins, Colo., May 2, 2011 – Advanced Energy Industries, Inc. (Nasdaq GM: AEIS) today announced financial results for the first quarter ended March 31, 2011. The company posted first quarter sales of $137.7 million, operating income of 17.7%, and earnings of $0.43 per diluted share from continuing operations.

“Advanced Energy had another quarter of solid financial and organizational performance. Our strategy to transition the company to a diversified business model paid dividends this quarter as increased shipments in our thin films business minimized the seasonality of our renewables business,” said Dr. Hans Betz, chief executive officer.

Total revenue of $137.7 million was split between Thin Films at $100.1 million and $37.6 million in the Renewables Business Unit. Thin films sales were primarily driven by strength in the semiconductor market. Renewables sales were impacted by the North American market first quarter seasonality, but delivered record bookings of $65.5 million for the quarter.

“We are very excited about our announcement today that our inverters have been chosen for two major Utility projects: a 150MW project with Zachry in Arizona and a 35MW project in California with Cupertino Electric, demonstrating the differentiated reliability and efficiency of our inverters and the subsequent impact on the levelized cost of energy. We are seeing a growing number of larger, Utility scale projects as the solar market continues its expansion,” said Dr. Hans Betz, chief executive officer.

Operating income grew to $24.4 million or 17.7% of revenue, the 8^th consecutive quarter of improved operating results. This continued strength was the result of our aggressive management of operating expenses as we

continue to refine our strategic business units. Net income from continuing operations was $18.8 million or $0.43 per diluted share, compared to net income from continuing operations of $19.7 million or $0.45 per diluted share in the fourth quarter of 2010. This decline was due to an increase in the company’s effective tax rate to 25% in the first quarter of 2011 from 19% in the fourth quarter of 2010.

Bookings for the first quarter were $184.0 million, compared to $83.2 million in the first quarter of 2010.

Thin Films Business Unit

Thin Films business unit sales climbed to $100.1 million versus $67.4 million in the same period of 2010, a 49% improvement year over year. This growth reflects the continued strength in the semiconductor industry and demonstrated our strength in advanced power solutions for Etch and Deposition applications. We also benefitted from another strong quarter in the solar panel and glass market as we continue to leverage our leading position in crystalline silicon processing equipment and strategic customer relationships to address the current growth in China.

Renewables Business Unit

Renewables business unit sales were $37.6 million in the quarter versus $2.3 million in the same period of 2010. This significant year over year improvement reflects the acquisition of PV Powered as well continued growth of the North American solar market. Our focus on building a leading position in the strategic commercial and Utility segments of the inverter market continued this quarter with record bookings reflecting the many growth opportunities ahead.

Second Quarter 2011 Guidance

The Company anticipates second quarter 2011 results from continuing operations, to be within the following ranges:

	•		Sales of $148 million to $160 million
	•		Earnings per share of $0.36 to $0.44

First Quarter 2011 Conference Call

Management will host a conference call tomorrow, Tuesday, May3, 2011, at 8:30 a.m. Eastern Daylight Time to discuss Advanced Energy’s financial results. Domestic callers may access this conference call by dialing (800) 299-6183. International callers may access the call by dialing (617) 801-9173. Participants will need to provide a conference pass code 79453281. For a replay of this teleconference, please call (888) 286-8010 or (617) 801-6888, and enter the pass code 79453281. The replay will be available for two weeks following the

conference call. A webcast will also be available on the Investor Relations web page at http://ir.advanced-energy.com.

About Advanced Energy

Advanced Energy (NASDAQ: AEIS — News) is a global leader in innovative power and control technologies forthin-film manufacturing and high-growth solar-power generation. Advanced Energy is headquartered in Fort Collins, Colorado, with dedicated support and service locations around the world. For more information, go to www.advanced-energy.com.

Forward-Looking Language

The Company’s expectations with respect to guidance to financial results for the second quarter ending June 30, 2011 and statements that are not historical information are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements are subject to known and unknown risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Such risks and uncertainties include, but are not limited to: the effects of global macroeconomic conditions upon demand for our products, the volatility and cyclicality of the industries the company serves, particularly the semiconductor industry, the continuation of RPS (renewable portfolio standards), the timing and availability of incentives and grant programs in the US and Europe related to the renewable energy market, the timing of orders received from customers, the company’s ability to realize benefits from cost improvement efforts, the ability to source materials and manufacture products, and unanticipated changes to management’s estimates, reserves or allowances. These and other risks are described in Advanced Energy’s Form 10-K, Forms 10-Q and other reports and statements filed with the Securities and Exchange Commission. These reports and statements are available on the SEC’s website at www.sec.gov. Copies may also be obtained from Advanced Energy’s website at www.advancedenergy.com or by contacting Advanced Energy’s investor relations at 970-407-6555. Forward-looking statements are made and based on information available to the company on the date of this press release. The company assumes no obligation to update the information in this press release.

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ADVANCED ENERGY INDUSTRIES, INC.

		Three Months Ended
		March 31,								December 31,
		2011				2010				2010
SALES		$	137,652			$	69,687			$	148,653
COST OF SALES			75,607				40,480				83,910
GROSS PROFIT			62,045				29,207				64,743
			45.1	%			41.9	%			43.6	%
OPERATING EXPENSES:
Research and development			15,862				11,142				15,275
Selling, general and administrative			20,905				12,229				24,586
Amortization of intangible assets			921				—				920
Total operating expenses			37,688				23,371				40,781
INCOME FROM OPERATIONS			24,357				5,836				23,962
Other income, net			663				385				392
Income from continuing operations before income taxes			25,020				6,221				24,354
Provision for income taxes			6,254				1,371				4,624
INCOME FROM CONTINUING OPERATIONS			18,766				4,850				19,730
Gain on sale of discontinued operations, net of tax			—				—				12,531
Results from discontinued operations, net of tax			140				1,367				(853	)
INCOME FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES			140				1,367				11,678
NET INCOME		$	18,906			$	6,217			$	31,408
Basic weighted-average common shares outstanding			43,440				42,074				43,315
Diluted weighted-average common shares outstanding			44,133				42,680				43,796
EARNINGS PER SHARE:
CONTINUING OPERATIONS:
BASIC EARNINGS PER SHARE		$	0.43			$	0.12			$	0.46
DILUTED EARNINGS PER SHARE		$	0.43			$	0.11			$	0.45
DISCONTINUED OPERATIONS
BASIC EARNINGS PER SHARE		$	0.00			$	0.03			$	0.27
DILUTED EARNINGS PER SHARE		$	0.00			$	0.03			$	0.27
NET INCOME:
BASIC EARNINGS PER SHARE		$	0.44			$	0.15			$	0.73
DILUTED EARNINGS PER SHARE		$	0.43			$	0.15			$	0.72

ADVANCED ENERGY INDUSTRIES, INC.
CONDENSED CONSOLIDATED BALANCE SHEETS
(in thousands)

		March 31,				December 31
		2011				2010
ASSETS
Current assets:
Cash and cash equivalents		$	132,418			$	130,914
Marketable securities			7,620				9,640
Accounts receivable, net			121,236				119,893
Inventories, net			90,109				77,593
Deferred income taxes			7,689				7,510
Income taxes receivable			9,435				6,061
Other current assets			9,179				10,156
Total current assets			377,686				361,767
Property and equipment, net			36,210				34,569
Deposits and other			8,874				8,874
Goodwill and intangibles, net			95,860				96,781
Deferred income tax assets, net			3,166				3,166
Total assets		$	521,796			$	505,157
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable		$	51,974			$	56,185
Other accrued expenses			43,005				46,140
Total current liabilities			94,979				102,325
Long-term liabilities			29,959				28,864
Total liabilities			124,938				131,189
Stockholders’ equity			396,858				373,968
Total liabilities and stockholders’ equity			521,796			$	505,157

ADVANCED ENERGY INDUSTRIES, INC.
SEGMENT INFORMATION
(in thousands)

		Three Months Ended
		March 31,								December 31,
		2011				2010				2010
SALES:
Thin Films		$	100,099			$	67,423			$	96,960
Renewables			37,553				2,264				51,693
Total Sales			137,652				69,687				148,653
OPERATING INCOME:
Thin Films		$	24,824
Renewables			2,512
Total segment operating income			27,336
Corporate expenses			(2,979	)
Other income, net			663
Income from continuing operations before income taxes		$	25,020