A non-volatile memory device includes a substrate having an active region defined by a device isolation region that has a trench and an air gap, a device isolation pattern positioned at a lower portion of the trench, a memory cell layer including a tunnel insulation layer, a trap insulation layer and a blocking insulation layer that are sequentially stacked on the active region and one of which extends from the active region toward the device isolation region encloses top of the air gap whose bottom is defined by a layer other than that of the top, and a control gate electrode positioned on the cell structure. The one of the insulation layer extending includes a recess at a region corresponding to the center of the air gap.