A semiconductor device capable of reducing an inductance is provided. In the semiconductor device in which a rectification MOSFET, a commutation MOSFET, and a driving IC that drives these MOSFETs are mounted on one package, the rectification MOSFET, a metal plate, and the commutation MOSFET are laminated. A current of a main circuit flows from a back surface of the package to a front surface thereof. The metal plate is connected to an output terminal via a wiring in the package. Wire bondings are used for wirings for connecting the driving IC, the rectification MOSFET, and the commutation MOSFET, all terminals being placed on the same plane. For this reason, the inductance becomes small and also a power source loss and a spike voltage are reduced.