According to one embodiment, there is provided a semiconductor device including a stacked body, a semiconductor columnar member, an insulating film, and a structure. The stacked body is disposed above a semiconductor substrate. In the stacked body, a conductive film and an insulating layer are alternately disposed in a stacking direction. The semiconductor columnar member penetrates the stacked body in the stacking direction. The insulating film surrounds the semiconductor columnar member and penetrates the stacked body in the stacking direction. The structure is disposed in a peripheral circuit region on the semiconductor substrate. The peripheral circuit region is a region including a plurality of circuit blocks. The structure has a plate-shaped portion extending at least between the plurality of circuit blocks.