According to one embodiment, a semiconductor device includes a semiconductor section, a control electrode, and a first electrode. The semiconductor section extends in a first direction. The control electrode is provided across a first insulating film from the semiconductor section in a second direction. The semiconductor section includes first, second, third, and fourth semiconductor regions. The first semiconductor region has a first conductivity type. The second semiconductor region has a second conductivity type, and is provided on the first semiconductor region to oppose the control electrode. The third semiconductor region has the first conductivity type, and is provided on the second semiconductor region. The fourth semiconductor region has the second conductivity type, and is provided together with the third semiconductor region. The first electrode is provided on the semiconductor section. The fourth semiconductor region is provided displaced to opposite side of the semiconductor section from the control electrode.