To provide a semiconductor device having a novel structure. To provide a semiconductor device excellent in reducing power consumption. A memory cell including an SRAM capable of backing up data to the nonvolatile memory and a peripheral circuit of the memory cell are configured to offer different power gating states. In a first period, which is extremely short, the bit line is brought into an electrically floating state by turning off the switch. In a second period, which is longer than the first period, power gating is performed on the memory cell. In a third period, which is longer than the second period, power gating is performed on the memory cell and the peripheral circuits.