Abstract: A nonvolatile semiconductor memory device includes: a substrate; a stacked body with a plurality of dielectric films and electrode films alternately stacked therein, the stacked body being provided on the substrate and having a step in its end portion for each of the electrode films; an interlayer dielectric film burying the end portion of the stacked body; a plurality of semiconductor pillars extending in the stacking direction of the stacked body and penetrating through a center portion of the stacked body; a charge storage layer provided between one of the electrode films and one of the semiconductor pillars; and a plug buried in the interlayer dielectric film and connected to a portion of each of the electrode films constituting the step, a portion of each of the dielectric films in the center portion having a larger thickness than a portion of each of the dielectric films in the end portion.