A manufacturing method of a BGA, includes the steps of: providing a semiconductor chip having electrode pads; and removing a natural oxide film formed on the surface of each of the electrode pads. Further, a first film comprised of a conductive member is formed on the surface of the electrode pad exposed by removing the natural oxide film, a wire is connected with the first film, and part of the wire is brought into contact with the electrode pad to form an alloy layer at the interface between the wire and the electrode pad. The crystal structure of the first film is comprised of a body-centered cubic lattice or a hexagonal close-packed lattice. The cost of the semiconductor device can be reduced while the bonding reliability of wire bonding of the semiconductor device is ensured.