The semiconductor device includes a plurality of conductive line structures including a plurality of conductive lines spaced apart from a substrate with an insulating film there between and insulating capping layers that are formed on each of plurality of conductive lines; an insulating spacer that is disposed between the plurality of conductive line structures and covers both side walls of each of the plurality of conductive line structures to define a contact hole having a first width in a first direction parallel to an upper surface of the substrate; a contact plug filling a portion of the contact hole; and a landing pad that is connected to the contact plug and vertically overlapping with one of the plurality of conductive line structures.