A nonvolatile memory device according to an embodiment includes a substrate, and a gate structure disposed on the substrate and including a hole pattern. The gate structure includes at least one gate electrode layer and at least one interlayer insulation layer which are alternately stacked, and the gate electrode layer protrudes toward a center of the hole pattern relative to the interlayer insulation layer. The nonvolatile memory device includes a first functional layer disposed along a sidewall surface of the gate structure inside the hole pattern, a second functional layer disposed on the first functional layer inside the hole pattern, and a channel layer extending in a direction perpendicular to the substrate inside the hole pattern and disposed to contact a cell portion of the second functional layer. The cell portion of the second functional layer indirectly covers a sidewall surface of the gate electrode layer.