Abstract: According to one embodiment, a semiconductor device, includes first to third electrodes, first to third layers, and an insulating member. A position of the third electrode is between a position of the first electrode and a position of the second electrode. The first layer includes first to fifth partial regions. The fourth partial region is located between the first and third partial regions. The fifth partial region is located between the third and second partial regions. The second layer includes a first compound region provided between the third partial region and the third electrode. The third layer includes first to third portions. The third portion is located between the third partial region and the first compound region. The insulating member includes a first insulating region. The first insulating region is located between the first compound region and the third electrode.