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		CLIENT/MATTER NUMBER 115859-0101
	November 6, 2017

Advanced Energy Industries, Inc.

1625 Sharp Point Drive

Fort Collins, CO 80525

Ladies and Gentlemen:

We have acted as counsel for Advanced Energy Industries, Inc., a Delaware corporation (the “Company”), in conjunction with the preparation of a Registration Statement on Form S-8 (the “Registration Statement”) to be filed by the Company with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), relating to 2,500,000 shares (the “Registered Shares”) of the Company’s common stock, par value $0.001 per share (“Common Stock”), that may be issued pursuant to the Advanced Energy Industries, Inc. 2017 Omnibus Incentive Plan (the “2017 Plan”).

In connection with our representation, we have examined: (a) the 2017 Plan and related documents; (b) the Registration Statement, including the exhibits (including those incorporated by reference) constituting a part of the Registration Statement; (c) the Certificate of Incorporation of the Company and the By-Laws of the Company, as amended to date; (d) the resolutions of the Company’s Board of Directors relating to the 2017 Plan and the issuance of Common Stock thereunder; and (e) such other corporate proceedings, documents and records as we have deemed necessary or appropriate to enable us to render this opinion.

In our examination of the above-referenced documents, we have assumed the genuineness of all signatures, the authenticity of all documents, certificates and instruments submitted to us as originals and the conformity with the originals of all documents submitted to us as copies.

Based on the foregoing, we are of the opinion that the Registered Shares, if and when issued by the Company pursuant to the terms and conditions of the 2017 Plan and as contemplated by the Registration Statement, will be legally issued, fully paid and nonassessable.

We consent to the use of this opinion as an exhibit to the Registration Statement. In giving our consent, we do not admit that we are “experts” within the meaning of Section 11 of the Securities Act or within the category of persons whose consent is required by Section 7 of the Securities Act.

Very truly yours,

/s/ Foley & Lardner LLP

Foley & Lardner LLP

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