EXHIBIT 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (Registration Nos. 333-30689, 333-30691, 333-44760, 333-73192, 333-101727, 333-101751, 333-109282, 333-128251, 333-130150, 333-151039, 333-156626, 333-156627, 333-166908, 333-174562, 333-181269, and 333-181270) and Form S-3 (Registration Nos. 333-196003, 33-48089, 333-42660, and 333-109211) of 3M Company of our report dated February 12, 2015 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Minneapolis, Minnesota

February 12, 2015

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