As operations of an SRAM, there are writing and reading operations, and only a portion of the whole memory operates during performing these operations, while another portion thereof stores a value. By lowering a current consumed in a period of storing this value, a semiconductor device with low power consumption is provided. The present invention provides a semiconductor device with reduced drive voltage in a period of storing a value, compared with a period of writing a value or a period of reading a value. Such a semiconductor device includes a power supply control circuit including an OR circuit electrically connected to a word line, an inverter circuit electrically connected to the OR circuit, and a transistor electrically connected to the OR circuit and the inverter circuit.