A semiconductor device includes a semiconductor layer of a first conductivity type having a first principal surface on one side and a second principal surface on the other side, the semiconductor layer in which a device formation region and an outer region outside the device formation region are set, a channel region of a second conductivity type formed in a surface layer portion of the first principal surface of the semiconductor layer in the device formation region, an emitter region of a first conductivity type formed in a surface layer portion of the channel region, a gate electrode formed at the first principal surface of the semiconductor layer in the device formation region, the gate electrode facing the channel region across a gate insulating film, a collector region of a second conductivity type formed in a surface layer portion of the second principal surface of the semiconductor layer in the device formation region, an inner cathode region of a first conductivity type formed in the surface layer portion of the second principal surface of the semiconductor layer in the device formation region, and an outer cathode region of a first conductivity type formed in the surface layer portion of the second principal surface of the semiconductor layer in the outer region.