A memory device includes first electrode layers stacked in a first direction, a first semiconductor layer piercing the first electrode layers in a first direction, a first insulating film surrounding the first semiconductor layer, and a semiconductor base connected to the first semiconductor layer. The first insulating film includes a first film, a second film, and a third film provided in order in a second direction from the first semiconductor layer toward one of first electrode layers. Spacing in the first direction between the second film and the semiconductor base is wider than a film thickness of the third film in the second direction. A minimum width of an outer perimeter of the first semiconductor layer is substantially the same as a width of an outer perimeter at a portion of the first semiconductor layer piercing the most proximal first electrode layer.