A semiconductor device includes an insulating film base member and a wiring pattern that is formed on the insulating film base member. The wiring pattern has a surface, with at least a peripheral section of the surface being a peeled surface of the wiring pattern peeled from the insulating film base member. The semiconductor device further includes a plating layer that covers the surface of the wiring pattern, and an IC chip that has an active surface with a bump bonded to the wiring pattern. The peeled surface of the wiring pattern is peeled from the insulating film base member around a bonding position of the wiring pattern bonded with the bump.