Disclosed are a separator for a fuel cell realizing both the high electrical conductivity and the corrosion resistance and enabling using stably for a long period of time in the fuel cell and a manufacturing method for it. The separator for a fuel cell 1 includes a substrate 2 composed of pure aluminum or aluminum alloy and a plating layer 3 formed on the substrate 2, wherein the plating layer 3 has a copper layer 3a formed in the substrate 2 side and a tin layer 3b formed on the copper layer 3a, the tin layer 3b is formed in an uppermost layer, the thickness of the copper layer 3a is 0.10 μm or above, and the value obtained by dividing the thickness of the tin layer 3b by the thickness of the copper layer 3a is 0.1-50.