A metal member includes: a metal base; a first plating layer of nickel and unavoidable impurities, which is formed on the metal base; a second plating layer of nickel, phosphorus and unavoidable impurities, which is formed on the first plating layer; a third plating layer of a gold alloy and unavoidable impurities, which is formed on the second plating layer; and a fourth layer formed on the third plating layer by a sealing process, wherein the first plating layer has a thickness of 0.5 to 2.5 μm and the second plating layer has a thickness of 0.05 to 0.5 μm, the sum of the thickness of the first plating layer and the thickness of the second plating layer being in the range of from 0.60 μm to 2.5 μm, and the third plating layer having a thickness of not less than 0.05 μm.