A semiconductor device including: a semiconductor region having a first semiconductor face and a second semiconductor face connected to the first semiconductor face and having an inclination with respect to the first semiconductor face; a gate insulating film formed on the first and on the second semiconductor faces; a gate electrode formed on the gate insulating film including a part on a boundary between the first semiconductor face and the second semiconductor face; a source impurity region formed in the semiconductor region so as to overlap the gate electrode within the first semiconductor face with the gate insulating film interposed between the source impurity region and the gate electrode; and a drain impurity region formed in the semiconductor region directly under the second semiconductor face at least.