Patent ID: 8896369

Claim:
A switching device comprising: a switching element that has a semiconductor substrate, a first electrode and a second electrode disposed on one surface of the semiconductor substrate, and a gate unit disposed between the first electrode and the second electrode on the one surface, and that makes a portion between the first electrode and the second electrode conductive by forming a channel region on the semiconductor substrate when a gate voltage exceeding a predetermined threshold voltage is applied to the gate unit; and a drive circuit that switches between ON and OFF of the switching element by applying the gate voltage to the gate unit of the switching element, wherein the semiconductor substrate includes a semiconductor-stacked body formed by having a first semiconductor layer and a second semiconductor layer stacked, has a hetero junction interface at a junction portion between the first semiconductor layer and the second semiconductor layer, and uses a 2-dimensional electron gas layer generated in the hetero junction interface as the channel region, the switching element has a hole injecting unit that includes an injecting electrode directly connected to the semiconductor substrate, the drive circuit has an injection driving unit that injects holes from the hole injecting unit into the hetero junction interface by applying an injection voltage to the injecting electrode, and the hole injection unit is disposed at a position between the first electrode and the gate unit, or between the gate unit and the second electrode.