A semiconductor device includes: a first electrode; a first semiconductor layer of first conductivity type provided on the first electrode; a second semiconductor layer of second conductivity type provided on the first semiconductor layer; a second electrode provided on the second semiconductor layer; a first trench reaching the first semiconductor layer from the second semiconductor layer; a first semiconductor region provided in the second semiconductor layer, the first semiconductor region being in contact with the first trench and the first semiconductor region having a higher concentration of impurities of second conductivity type than the second semiconductor layer; and a first insulating film provided in the second semiconductor layer and the first insulating film being in contact with the first semiconductor region.