According to one embodiment, a memory device includes a superlattice structure portion containing first chalcogen-compound layers and second chalcogen-compound layers differing in composition from the first chalcogen-compound layers are alternately deposited, a first layer provided on one of main surfaces of the superlattice structure portion in a deposition direction thereof, which has a larger energy gap than that of the superlattice structure portion, and a second layer provided on the other main surface of the superlattice structure portion in the deposition direction, which has a larger energy gap than that of the superlattice structure portion.