A state control register is provided in addition to the arithmetic circuit and communication circuit in a semiconductor device operated with wireless communication. Operation of an arithmetic circuit which consumes large power is stopped in transmitting or receiving data, that is, in the case where the operating magnetic field varies, whereas the arithmetic circuit can be operated in the case where the operating magnetic field does not vary. In the case where the operating magnetic field varies, a large capacity power supply is not required by realizing the function that is minimum required for the reception or transmission by a receiving circuit or a transmitting circuit. That is, a high-level arithmetic process can be carried out by a small-scale power supply circuit. In this manner, a high-functional and low-power consumption semiconductor device can be provided, which is a structure suitable for a semiconductor device provided with a large-scale circuit.