According to one embodiment, a semiconductor device includes first to fourth electrodes, a semiconductor member, and an insulating member. The semiconductor member includes first to sixth semiconductor regions. The third semiconductor region includes first and second partial regions. A part of the fourth semiconductor region is between the second partial and second semiconductor regions. The fifth semiconductor region is between the second partial region and a part of the fourth semiconductor region. The sixth semiconductor region is between the first electrode and the first semiconductor region. The second electrode is electrically connected to the second semiconductor region. The fourth electrode is between the first partial region and the third electrode. A part of the insulating member is provided between the semiconductor member and the third electrode, between the semiconductor member and the fourth electrode, and between the third and fourth electrodes.