A non-volatile memory device includes a tunnel oxide layer, a charge storage layer, a blocking insulating layer, and a gate electrode that are sequentially stacked, as well as an impurity diffusion layer in an active region at both sides of the gate electrode. The gate electrode crosses active regions between device isolation layers formed in a predetermined area of a semiconductor substrate, and an edge of the charge storage layer is extended to have a protruding part that protrudes from the gate electrode. In order to form a charge storage layer having a protruding part, a stack insulating layer including first to third insulating layers is formed in an active region between the device isolation layers formed in the substrate. A plurality of gate electrodes crossing the active region are formed on the stack insulating layer, and a sidewall spacer is formed on both sidewalls of the gate electrode. Using the sidewall spacer and the gate electrode, the stack insulating layer is etched to form a charge storage layer that protrudes from the sidewall of the gate electrode.