According to one embodiment, semiconductor memory device is capable of operating at a first mode and a second mode which is higher in speed than the first mode. The semiconductor memory device comprising: a semiconductor memory; a controller which controls the semiconductor memory; a connector which is provided with terminals for sending and receiving data to and from an external device; and a substrate on which the semiconductor memory, the controller, and the connector are mounted, the substrate comprising a plurality of wiring layers. The controller and the connector are mounted on an identical surface of the substrate. The substrate comprises a wiring which connects a mounting pad for the terminal for data transfer at the second mode of the connector and a mounting pad for a pin for data transfer at the second mode of the controller to each other on the wiring layer on a mounting surface for the connector and the controller.