A high-speed large-capacity phase-change memory is achieved. A semiconductor device according to the present invention includes: a plurality of memory planes MP; a plurality of storage information register groups SDRBK paired with the plurality of memory planes; and a chip control circuit CPCTL. The plurality of memory planes include a plurality of memory cells. Also, the plurality of storage information register groups temporarily retain information to be stored in the plurality of memory planes. Further, the chip control circuit includes a register which temporarily stores a value indicating volume of the storage information, and a first storage information volume is smaller than a second storage information volume. When the first storage information volume is written, the plurality of memory planes and the plurality of storage information register groups are activated during a first period. When the second storage information volume is written, the plurality of memory planes and the plurality of storage information register groups are activated during a second period. By such a structure, the first period is shorter than the second period.