According to one embodiment, a semiconductor device includes a first semiconductor region of a first conductivity type; a stacked body; a plurality of columnar portions; a plurality of first insulating portions having a wall configuration; and a plurality of second insulating portions having a columnar configuration. The columnar portions extend in a stacking direction of the stacked body. The columnar portions include a semiconductor body and a charge storage film. The first insulating portions extend in the stacking direction and in a first direction crossing the stacking direction. The second insulating portions extend in the stacking direction. A wide of the second insulating portions along a second direction crossing the first direction in a plane is wider than a wide of the first insulating portions along the second direction. The second insulating portions are disposed in a staggered lattice configuration.