There is provided a bonding wire that improves bonding reliability of a ball bonded part and ball formability and is suitable for on-vehicle devices. The bonding wire for a semiconductor includes a Cu alloy core material, and a Pd coating layer formed on a surface of the Cu alloy core material, and is characterized in that the Cu alloy core material contains Ni, a concentration of Ni is 0.1 to 1.2 wt. % relative to the entire wire, and a thickness of the Pd coating layer is 0.015 to 0.150 m.