According to one embodiment, a semiconductor device includes a first semiconductor region, a second semiconductor region, and a third semiconductor region. The first semiconductor region includes silicon carbide. A conductivity type of the first semiconductor region is a first conductivity type. The second semiconductor region includes silicon carbide. A conductivity type of the second semiconductor region is a second conductivity type. The third semiconductor region includes silicon carbide. A conductivity type of the third semiconductor is the second conductivity type. The third semiconductor region is provided between the first semiconductor region and the second semiconductor region. As viewed in a direction connecting the first semiconductor region and the second semiconductor region, an area of an overlapping region of the second semiconductor region and the third semiconductor region is smaller than an area of an overlapping region of the first semiconductor region and the second semiconductor region.