The semiconductor device of this embodiment includes: a first region of a first conductivity type SiC; a second region of a first conductivity type SiC, impurity concentration of first conductivity type of the second region being lower than impurity concentration of first conductivity type of the first region; a third region of a second conductivity type SiC provided between the first region and the second region; a Si layer provided on surfaces of the first, second, and third regions, a thickness of the Si layer on the third region being thicker than a thickness of the Si layer on the second region; a gate insulating film provided on the Si layer; and a date electrode provided on the gate insulating film.