SEMICONDUCTOR DEVICE

A semiconductor device is provided with: a semiconductor substrate (11) which is a drift layer (12); a base layer (13); a plurality of trenches (14); an emitter region (15); an emitter electrode (20);a collector layer (30); a collector electrode (31); a main gate electrode (18a) that generates an inversion layer and a dummy gate electrode (18b) that does not generate the inversion layer; a sharedgate pad (21a); a first element (24, 33) that is formed between the dummy gate electrode and the gate pad and that blocks or limits electrical continuity when a first voltage is applied, and permitselectrical continuity when a second voltage having a reversed polarity is applied; and a second element (25, 34) that is formed between the emitter electrode and a contact point between the dummy gateelectrode and the first element, and that permits electrical continuity when the first voltage is applied, and blocks or limits electrical continuity when the second voltage is applied. 半导体装置具备：作为漂移层(12)的半导体基板(11)；基极层(13)；多个沟槽(