A semiconductor device in which an input terminal is electrically connected to a first terminal of a first transmission gate; a second terminal of the first transmission gate is electrically connected to a first terminal of a first inverter and a second terminal of a functional circuit; a second terminal of the first inverter and a first terminal of the functional circuit are electrically connected to a first terminal of a second transmission gate; a second terminal of the second transmission gate is electrically connected to a first terminal of a second inverter and a second terminal of a clocked inverter; a second terminal of the second inverter and a first terminal of the clocked inverter are electrically connected to an output terminal; and the functional circuit includes a data holding portion between a transistor with small off-state current and a capacitor.