A first semiconductor layer of a first conductivity type, a first semiconductor region of a second conductivity type provided in an upper layer part thereof, a second semiconductor region of the first conductivity type provided in the upper layer part thereof, a gate trench penetrating through the first and second semiconductor regions in a thickness direction and a bottom surface thereof reaching inside of the first semiconductor layer, a gate insulating film in the gate trench, a gate electrode embedded in the gate trench, a second semiconductor layer of the second conductivity type provided so as to extend, from the bottom surface of the gate trench, a third semiconductor layer of the second conductivity type extending to a position deeper than the bottom surface of the gate trench, and a fourth semiconductor layer of the first conductivity type interposed between the second semiconductor layer and the third semiconductor layer in the position deeper than the bottom surface of the gate trench.