A semiconductor device includes a substrate, a semiconductor element, a connection pad, a plated layer, a wire, and an encapsulation resin. The substrate includes a main surface. The semiconductor element is mounted on the main surface and includes a main surface electrode. The connection pad is formed of Cu, arranged with respect to the substrate, separated from the substrate, and includes a connection surface. The plated layer is formed of Ni and partially covers the connection surface. The wire is formed of Al and bonded to the main surface electrode and the plated layer. The encapsulation resin encapsulates the semiconductor element, the connection pad, the plated layer, and the wire.