To provide a semiconductor device including a small-area circuit with high withstand voltage, an oxide semiconductor (OS) transistor is used as some of transistors included in a circuit handling an analog signal in a circuit to which high voltage is applied. The use of an OS transistor with high withstand voltage as a transistor requiring resistance to high voltage enables the circuit area to be reduced without lowering the performance, as compared to the case using a Si transistor. Furthermore, an OS transistor can be provided over a Si transistor, so that transistors using different semiconductor layers can be stacked, resulting in a much smaller circuit area.