To inexpensively provide a low-profiled copper foil for a printing wiring board by improving adhesiveness of the glossy surface of the copper foil to a resist as well as adhesion of this glossy surface with a resin substrate.

The electrolytic copper foil 1 is provided with the irregular and undefined-length veined undulation formed by electropolishing on the glossy surface 4 thereof. An electropolishing method includes electropolishing the glossy surface of the electrolytic copper foil using a sulfuric acid-copper sulfate bath as an electrolyte. Alternatively, the method includes arranging an anode 3 on the rough surface side 2 of the electrolytic copper foil and a cathode 5 on a glossy surface side, performing a smooth plating treatment on the rough surface by electrolysis, and then performing a reverse electropolishing treatment on the glossy surface.