According to one embodiment, a semiconductor device includes first to third electrodes, first and second semiconductor regions, and a first insulating film. The first semiconductor region includes a first partial region, a second partial region, a third partial region between the first and second partial regions, a fourth partial region between the first and third partial regions, and a fifth partial region between the third and second partial regions. The second semiconductor region includes a sixth partial region and a seventh partial region. The third electrode overlaps the sixth and seventh partial regions. The first insulating film includes a portion provided between the third electrode and the third partial region, between the third electrode and the fourth partial region, between the third electrode and the fifth partial region, between the third electrode and the sixth partial region, and between the third electrode and the seventh partial region.