Aspects of the invention can include a semiconductor device that includes an output stage IGBT and a Zener diode on the same semiconductor substrate. The IGBT can include a first p well layer, an n emitter region on the surface region of the first p well layer, a gate electrode deposited on a gate insulating film, and an emitter electrode on the emitter region. The Zener diode can include a p+ layer formed in the surface region of a second p well layer in the place different from the first p well layer and has a higher concentration than the second p well layer, an anode electrode in ohmic contact with the surface of the p+ layer, an n− layer having a lower concentration than the second p well layer, and a cathode electrode in Schottky contact with the surface of the n− layer.