A silicon carbide semiconductor device is provided with a semiconductor substrate (20) of silicon carbide of a first conductivity type, a hetero semiconductor region (60) forming a hetero-junction with the semiconductor substrate (20), an insulated gate including a gate electrode (40) and a gate insulator layer (30) formed on the semiconductor substrate (20) and adjoining to the hetero semiconductor region (60), a source electrode (80) electrically connected to the hetero semiconductor region (60) and a drain electrode (90) electrically connected to the semiconductor substrate (20).