A nonvolatile memory device includes a memory cell array including a plurality of memory cells, a first metal layer, a peripheral circuit configured to control the memory cell array, a second metal layer, and a pad. The first metal layer is disposed on the memory cell array and includes a plurality of cell region interconnections connected to the memory cell array. The second metal layer is disposed on the peripheral circuit and includes a plurality of peripheral region interconnections connecting the peripheral circuit and the plurality of cell region interconnections. The pad is disposed on the second metal layer and exchanges data, an address, or a command with the peripheral circuit during operation of the device. The second metal layer is lower than the first metal layer relative to a substrate of the device.