A semiconductor device is provided including: a semiconductor substrate having a first-conductivity-type drift region; a second-conductivity-type base region provided above the drift region inside the semiconductor substrate; an accumulation region provided between the drift region and the lower surface of the base region inside the semiconductor substrate, and having a lower second-conductivity-type carrier mobility than the drift region and the base region; a gate trench portion provided from an upper surface of the semiconductor substrate to an inside of the semiconductor substrate, where the gate trench portion is in contact with the base region; and a carrier passage region occupying at least a partial region between the accumulation region and the gate trench portion inside the semiconductor substrate, where the carrier passage region has a higher second-conductivity-type carrier mobility than the accumulation region.