A semiconductor device includes a first layer of a first conductivity type between a first and a second electrode. A second layer of the first conductivity type is between the first layer and the second electrode. A pair of third layers of a second conductivity type has a first portion in the first layer and a second portion contacting the second layer. A fourth layer is between the second layer and the second electrode and between the third layers and the second electrode. A fifth layer is between the fourth layer and the second electrode. A third electrode is adjacent to the second layer via a first insulating film. A fourth electrode is between the second electrode and the third electrode and adjacent to the fourth semiconductor layer via a second insulating film. The second insulating film is thinner than the first insulating film.