[Issues to be Solved] Second bonding failures caused by attached oxide of additive elements on high purity Au bonding wire are to be resolved.[Solution Means] Au alloy bonding wires comprising: 5-100 wt ppm Mg, 5-20 wt ppm In, 5-20 wt ppm Al, 5-20 wt ppm Yb, and residual Au of 99.995 wt % purity or higher, and adding 5-20 wt ppm Ca, and for these alloys adding at least one element among 5-20 wt ppm La, 5-20 wt ppm Lu, 5-100 wt ppm Sn, 5-100 wt ppm Sr to the alloy, and/or, moreover, adding 0.01-1.2 wt % Pd to these alloys. Bonding wire, which contains these trace additive elements do not cause a disturbance by accumulated contamination, because of contamination, which formed at ball formation by micro discharge and at the first bonding on the tip of the capillary, transferring to the wire at second bonding.