The present invention, material cost is inexpensive, ball bondability, excellent reliability of the thermal cycle test or reflow test, shelf life is good, providing a copper-based bonding wire to adapt to pitch for thinning the interest.
A core material composed mainly of copper, disposed on said core material, said core material, a bonding wire having an outer layer containing either one or both of different metals M and copper components and composition Te, the thickness of the outer layer is a bonding wire for a semiconductor device which is a 0.021～0.12Myuemu.