A semiconductor device according to the present invention includes a semiconductor layer provided with a gate trench, a first conductivity type source region formed to be exposed on a surface side of the semiconductor layer, a second conductivity type channel region formed on a side of the source region closer to a back surface of the semiconductor layer to be in contact with the source region, a first conductivity type drain region formed on a side of the channel region closer to the back surface of the semiconductor layer to be in contact with the channel region, a gate insulating film formed on an inner surface of the gate trench, and a gate electrode embedded inside the gate insulating film in the gate trench, while the channel region includes a channel portion formed along the side surface of the gate trench so that a channel is formed in operation and a projection projecting from an end portion of the channel portion closer to the back surface of the semiconductor layer toward the back surface.