Disclosed is a bonding wire for semiconductor, which ensures good wedge bonding even of palladium-plated lead frames and has excellent oxidation resistance, and in which copper or a copper alloy is used as a core wire. The bonding wire is characterized by comprising a core wire that comprises copper or a copper alloy, a coating layer that is arranged on the surface of the core wire, has a thickness of 10 to 200 nm and contains palladium, and an alloy layer that is arranged on the surface of the coating layer, has a thickness of 1 to 80 nm and contains a noble metal and palladium, wherein the noble metal is silver or gold, and the noble metal is contained in the alloy layer at a concentration of 10 to 75 vol% inclusive. In a measured result of the crystallization orientation of the bonding wire surface, the alloy layer contains surface crystal grains among which those having <111> crystal orientations angled at 15 degrees or less to a wire drawing direction occupy an areal percentage of 40% to 100%.