According to one embodiment, a semiconductor storage device includes: a stacked body in which a plurality of conductive layers are separated from each other and are stacked; a pillar which extends in a stacking direction and includes memory cells to be formed at intersections with at least some of the plurality of conductive layers; an upper insulating layer arranged on the stacked body; a plug which extends in the stacking direction inside the upper insulating layer and is connected to the upper end portion of the pillar; and a spacer insulating layer which surrounds the plug and has a lower dielectric constant than a dielectric constant of the upper insulating layer.