A conventional charge pump circuit requires a step-up circuit or the like for turning on or off a transistor. Therefore, it has a problem of an increase in circuit scale, which leads to increases in circuit area and power consumption. One feature is to provide a charge pump circuit including a first transistor, a switch, a first capacitor, a second capacitor, and an inverter, in which one electrode of the first transistor is connected to a first potential, an output side of the inverter is connected to the other electrode of the first transistor and one side of the switch through the first capacitor, the other side of the switch is connected to a second potential through the second capacitor.