A nonvolatile semiconductor memory device, includes: a stacked structural unit including electrode films alternately stacked with inter-electrode insulating films; a first and second semiconductor pillars piercing the stacked structural unit; a connection portion semiconductor layer to electrically connect the first and second semiconductor pillars; a connection portion conductive layer opposing the connection portion semiconductor layer; a memory layer, an inner insulating film, and an outer insulating film provided between the first and second semiconductor layers and the electrode films and between the connection portion semiconductor layer and the connection portion conductive layer. At least a portion of a face of the connection portion conductive layer opposing the outer insulating film is a curved surface having a recessed configuration on a side of the outer insulating film.