The semiconductor device and a driving method thereof

To provide a semiconductor device in which power consumption can be reduced and operation delay due to a stop and a restart of supply of power supply voltage can be suppressed and a driving method thereof. A potential corresponding to data held in a period during which power supply voltage is continuously supplied is saved to a node connected to a capacitor before the supply of power supply voltage is stopped. By utilizing change of channel resistance of a transistor whose gate is the node, data is loaded when the supply of power supply voltage is restarted.