A nonvolatile memory device including: a first semiconductor layer including word lines, bit lines, first and second upper substrates adjacent to each other and a memory cell array, wherein the memory cell array includes a first vertical structure on the first upper substrate and a second vertical structure on the second upper substrate; and a second semiconductor layer under the first semiconductor layer, wherein the second semiconductor layer includes a lower substrate that includes row decoder and page buffer circuits, wherein the first vertical structure includes a first via area in which a first through-hole via is provided, wherein the first through-hole via passes through the first vertical structure and connects a first bit line and a first page buffer circuit, and the second vertical structure includes a first partial block, wherein the first partial block overlaps the first via area.