The present disclosure provides a semiconductor device comprising: a block separator including a semiconductor film and a multi-layered insulating film, wherein the multi-layered insulating film surrounds the semiconductor film; memory block stacks divided from each other by the block separator, each memory block stack including interlayer insulating films and conductive patterns alternately stacked, wherein the conductive patterns are coupled to memory cells; and channel structures passing through the memory block stacks and electrically coupled to the memory cells.