According to the embodiment, a nonvolatile semiconductor memory that includes a plurality of banks capable of operating in parallel, a command analyzing unit that, upon receiving a power management command from a host, analyzes the received power management command, and a recording control unit that dynamically and variably controls an upper limit of the number of banks to be operated in parallel at a time of writing in accordance with an analysis result by the command analyzing unit are included, thereby suppressing the upper limit of a power consumption in accordance with an instruction from the host.