A semiconductor device transmits a wireless signal to a power reception device that charges a battery, transmits a charge completion signal when the battery charge is completed, and transmits a response signal in reply to a query signal in the wireless signal. The semiconductor device includes a drive control circuit, a reception circuit, and a controller. The controller can control, when the reception circuit does not receive the response signal or receives the charge completion signal, the drive control circuit to transmit communication capable power that makes it possible to communicate with the power reception device and control, when the reception circuit receives the response signal and does not receive the charge completion signal, the drive control circuit to transmit charging power capable of charging the battery of the power reception device by the wireless signal, the charging power being higher than the communication capable power.