Abstract: Provided is a semiconductor device capable of reducing switching loss at turn-off while suppressing conduction loss. An emitter p? layer 11, a collector p layer 23, a drift layer 10, an emitter electrode 18, a collector electrode 28, an emitter-side gate electrode 17, an emitter n layer 12, a collector p? layer 23a, a collector-side gate electrode 27, and a collector n layer 22 configure a semiconductor device 1, and a total length of a first facing region of the emitter-side gate electrode 17 in a gate width direction facing an emitter layer p? 11 via a gate insulating film 15 is longer than the total length in the gate width direction of a second facing region of a collector-side gate electrode 27 facing an impurity layer 23a via a collector-side gate insulating film 25.