The silicon carbide semiconductor device includes: a silicon carbide layer; a silicon dioxide layer provided above the silicon carbide layer and containing nitrogen; and a transition region arranged between the silicon carbide layer and the silicon dioxide layer, and containing carbon, oxygen, and nitrogen, wherein the maximum nitrogen concentration in the transition region is 1.0×1020 cm−3 or higher. The maximum nitrogen concentration in the transition region is five or more times higher than the maximum nitrogen concentration in the silicon dioxide layer.