[Issues to be solved] Providing enhanced bonding reliability of Au alloy bonding wire with low electrical resistivity to Al electrode of semiconductor device, and its application of semiconductor device is bonded with Al electrode pad by the same wire. [Solution means] Au alloy bonding wire comprising: 0.02 - 0.3 mass % Ag, total amount of 10 - 200 mass ppm at least one element of Ge and/or Si, and/or total amount of 10 - 200 mass ppm at least one element of Al and/or Cu, with residual of Au. Moreover, Al and/or Al alloy pad bonded with the above Au alloy bonding wire.