A semiconductor device includes a first-conductivity-type semiconductor layer that includes a first main surface on one side and a second main surface on the other side, an IGBT region that includes an FET structure and a second-conductivity-type collector region formed in a surface layer portion of the second main surface, the FET structure including a second-conductivity-type body region formed in a surface layer portion of the first main surface, a first-conductivity-type emitter region formed in a surface layer portion of the body region, and a gate electrode that faces both the body region and the emitter region across a gate insulating layer, a diode region that a includes second-conductivity-type first impurity region formed in the surface layer portion of the first main surface and a first-conductivity-type second impurity region formed in the surface layer portion of the second main surface.