To provide a semiconductor device with reduced power consumption that includes a selection transistor. To provide a semiconductor device capable of high-speed operation without increasing a power supply potential. A buffer circuit connected to a gate line has a function of generating a potential higher than a high power supply potential by using the high power supply potential and outputs the potential in response to a selection signal. Specifically, a bootstrap circuit boosts a high power supply potential that is input to an inverter that is the closest to an output side in the buffer circuit. Further, the bootstrap circuit boosts the potential when the gate line is selected, and does not boost the potential when the gate line is not selected.