A semiconductor device includes a semiconductor substrate, a drift layer of a first conductivity type, a buffer layer of the first conductivity type, a first semiconductor layer, and a second semiconductor layer. The first semiconductor layer and the second semiconductor layer are provided on the side of the second main surface of the semiconductor substrate with respect to the buffer layer. The first semiconductor layer and the second semiconductor layer are arranged in this order in a direction from the second main surface toward the first main surface of the semiconductor substrate. The first semiconductor layer and the second semiconductor layer have conductivity types identical to each other. The second semiconductor layer has a larger number of atoms of impurities per unit volume than the first semiconductor layer.