Semiconductor device and method of manufacturing the same

Embodiments provide a semiconductor device capable of appropriately forming a semiconductor layer in an opening and a method of manufacturing the same. According to one embodiment, a semiconductor device includes: a first laminated film including a plurality of first electrode layers spaced apart from each other; an insulating layer provided on the first laminated film; and a second laminated film provided on the insulating layer and including a plurality of second electrode layers spaced apart from each other. The device is further provided with a columnar portion that includes a first insulating film, a charge storage layer, a second insulating film, and a semiconductor layer provided in this order in the first laminated film, the insulating layer, and the second laminated film, and that extends in a first direction from the first laminated film toward the second laminated film. The columnar portion in the insulating layer includes a first portion having a first width in a second direction intersecting the