A memory device has a vertical structure in which a row decoder, a page buffer, and a peripheral circuit are disposed under a memory cell array. The row decoder and the page buffer may be asymmetrically disposed. The peripheral circuit is disposed in an area where the row decoder and the page buffer are not disposed. The row decoder and the page buffer may be symmetrically disposed with respect to an interface of planes. The peripheral circuit may be disposed in an area including a part of the interface of the planes.