A mesa type p-n junction diode silicon carbide semiconductor device that includes a first silicon carbide semiconductor substrate, a first drift layer formed on the silicon carbide semiconductor substrate, a second anode layer formed on the drift layer, a mesa structure having a flat mesa bottom portion formed in an outer periphery thereof and having a mesa side wall obliquely formed with respect to a top face of the anode layer in a cross-section ranging from the anode layer to the drift layer, a second lightly doped region formed from an edge of the anode layer to the mesa bottom portion, and a second highly doped region formed on the side of the mesa side wall in the lightly doped region in contact with the edge of the anode layer and in a portion connected to the mesa bottom portion at a lower part of the mesa side wall.