A semiconductor device includes a semiconductor substrate, a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, a diode trench gate, and an electrode layer. The first semiconductor layer is provided as a surface layer on the upper surface side of the semiconductor substrate. The second semiconductor layer is provided below the first semiconductor layer. The diode trench gate includes a diode trench insulation film formed along, out of the inner wall of the trench, a lower side wall and a bottom that are located below an upper side wall located on the upper end side of the trench. The diode trench gate includes a diode trench electrode provided inside the trench. The electrode layer covers the upper side wall of the trench. The first semiconductor layer is in contact with the electrode layer on the upper side wall of the trench.