A nonvolatile semiconductor memory device, includes: a stacked structural unit including electrode films alternately stacked with inter-electrode insulating films; first and second semiconductor pillars piercing the stacked structural unit; a connection portion semiconductor layer electrically connect the first and second semiconductor pillars; a connection portion conductive layer provided to oppose the connection portion semiconductor layer; a memory layer and an inner insulating film provided between the first and semiconductor pillars and each of the electrode films, and between the connection portion conductive layer and the connection portion semiconductor layer; an outer insulating film provided between the memory layer and each of the electrode films; and a connection portion outer insulating film provided between the memory layer and the connection portion conductive layer. The connection portion outer insulating film has a film thickness thicker than a film thickness of the outer insulating film.