A semiconductor memory device including: a common source line; a substrate on the common source line; a plurality of gate electrodes arranged on the substrate and spaced apart from each other in a first direction perpendicular to a top surface of the common source line; a plurality of insulation films arranged among the plurality of gate electrodes; a plurality of channel structures penetrating through the plurality of gate electrodes and the plurality of insulation films in the first direction; and a plurality of residual sacrificial films arranged on the substrate and spaced apart from each other in the first direction, wherein the plurality of gate electrodes are disposed on opposite sides of the plurality of residual sacrificial films.