A sensor device includes a first sensor unit, a control IC configured to switch a power supply route, a power supply, a DC converter, and a regulator configured to regulate the voltage. A power supply route A and a power supply route B is provided as a power supply route from the power supply to the sensor unit and the control IC. In the power supply route A, the sensor unit is not electrically conducted to the power supply, and the control IC is directly connected to the power supply. In the power supply route B, the power supply, the DC converter, and the regulator are connected in series, output of the regulator is supplied to the sensor unit, and output of the DC converter is supplied to the control IC. The control IC switches between the power supply route A and the power supply route B according to an operating state of the sensor unit.