A nonvolatile memory device includes a first channel comprising a pair of first pillars vertically extending from a substrate and a first coupling portion positioned under the pair of first pillars and coupling the pair of first pillars, a second channel adjacent to the first channel comprising a pair of second pillars vertically extending from the substrate and a second coupling portion positioned under the pair of second pillars and coupling the pair of second pillars, a plurality of gate electrode layers and interlayer dielectric layers alternately stacked along the first and second pillar portions, and first and second trenches isolating the plurality of gate electrode layers between the pair of first pillar portions and between the pair of second pillar portions, respectively.