SEMICONDUCTOR DEVICE BONDING WIRE

To provide a novel Cu bonding wire that achieves a favorable FAB shape and a favorable bondability of the 2nd bonded part, and further achieves favorable bond reliability of the 1st bonded part in a high-temperature environment. The bonding wire for semiconductor devices includes: a core material of Cu or Cu alloy; and a coating layer containing conductive metal other than Cu formed on a surface of the core material, wherein the coating layer has a region containing Ni as a main component on a core material side, and has a region containing Au and Ni on a wire surface side, in a thickness direction of the coating layer, a thickness of the coating layer is 10 nm or more and 130 nm or less, a ratio CAu/CNi of a concentration CAu (mass%) of Au to a concentration CNi (mass%) of Ni relative to the entire wire is 0.02 or more and 0.7 or less, and a concentration of Au at the surface of the wire is 10 atomic% or more and 90 atomic% or less