According to an embodiment, a semiconductor memory device capable of stably operating even when an element is shrunk is provided. The semiconductor memory device of the embodiment includes: first and second diodes serially connected between power sources of two different potentials, formed by nanowires, and exhibiting negative differential resistances; and a select transistor connected between the first diode and the second diode. The nanowires are preferably silicon nanowires. The thickness of the silicon nanowires is preferably 8 nm or less.