Exhibit 23

CONSENT OF INDEPENDENT REGISTERED ACCOUNTING FIRM

We consent to the incorporation by reference in Registration Statement Nos. 333-33790, 333-126577 and 333-179042 on Form S‑8 and in Registration Statement No. 333-187306 on Form S-3, relating to the consolidated financial statements of Avista Corporation and subsidiaries, and the effectiveness of Avista Corporation’s internal control over financial reporting, appearing in this Annual Report on Form 10‑K of Avista Corporation for the year ended December 31, 2014.

/s/ Deloitte & Touche LLP

Seattle, Washington

February 25, 2015