The semiconductor device includes a first semiconductor region of a first conductivity type partially extending to a top face of a semiconductor substrate; a second semiconductor region of a second conductivity type formed on the first semiconductor region; a third semiconductor region of the first conductivity type formed on the second semiconductor region; a fourth semiconductor region of the second conductivity type formed on the second semiconductor region and adjacent to the third semiconductor region; a trench penetrating through the second semiconductor region and the third semiconductor region; a gate insulating film formed on an inner wall of the trench; and a gate electrode formed on the gate insulating film within the trench. The semiconductor device further includes a fifth semiconductor region of the second conductivity type formed on the second semiconductor region to be sandwiched between the fourth semiconductor region and a portion of the first semiconductor region positioned on a side of the fourth semiconductor region. An impurity concentration in the fifth semiconductor region is higher than an impurity concentration in the second semiconductor region.