A sensor device (1,1A,1B) comprising: a first sensor unit configured to measure a measurement target and to generate measurement data; a controller configured to switch a power supply route; a communicator configured to transmit said measurement data of the first sensor unit, a power supply configured to supply power to the first sensor unit, the controller and the communicator; a converter configured to convert a voltage, the converter being configured to be connected to the power supply and to output a voltage to the controller and the communicator; and a regulator configured to regulate the voltage, the regulator being configured to be connected to the output of the converter and to output a regulated voltage to the first sensor unit, and wherein a power supply route A, a power supply route B and a power supply route C are provided as the power supply route from the power supply to the first sensor unit the controller and the communicator, the controller being adapted to control switches (SW1, SW2, SW3) to switch between the power supply route A, the power supply route B and the power supply route C according to an operating state of the first sensor unit or the communicator, wherein in the power supply route A the first sensor unit being not electrically conducted to the power supply, the controller being directly connected to the power supply, the converter being not connected to the power supply, the regulator being not connected to the output of the converter, and the controller and communicator being directly connected to the power supply, in the power supply route B the power supply, the converter, and the regulator being connected in series, output of the regulator being supplied to the first sensor unit, output of the converter being supplied to the controller, the converter being connected to the power supply, the regulator being connected to the output of the converter, and the controller and the communicator receiving the output voltage of the converter, and in the power supply route C the power supply and the converter being connected to each other, the output of the converter being supplied to the controller and the communicator, the first sensor unit being not electrically conducted to the power supply, the converter being connected to the power supply, the regulator being not connected to the output of the converter, and the controller and the communicator receiving the output voltage of the converter. a first sensor unit configured to measure a measurement target and to generate measurement data; a controller configured to switch a power supply route; a communicator configured to transmit said measurement data of the first sensor unit, a power supply configured to supply power to the first sensor unit, the controller and the communicator; a converter configured to convert a voltage, the converter being configured to be connected to the power supply and to output a voltage to the controller and the communicator; and a regulator configured to regulate the voltage, the regulator being configured to be connected to the output of the converter and to output a regulated voltage to the first sensor unit, and wherein a power supply route A, a power supply route B and a power supply route C are provided as the power supply route from the power supply to the first sensor unit the controller and the communicator, the controller being adapted to control switches (SW1, SW2, SW3) to switch between the power supply route A, the power supply route B and the power supply route C according to an operating state of the first sensor unit or the communicator, wherein in the power supply route A the first sensor unit being not electrically conducted to the power supply, the controller being directly connected to the power supply, the converter being not connected to the power supply, the regulator being not connected to the output of the converter, and the controller and communicator being directly connected to the power supply, in the power supply route B the power supply, the converter, and the regulator being connected in series, output of the regulator being supplied to the first sensor unit, output of the converter being supplied to the controller, the converter being connected to the power supply, the regulator being connected to the output of the converter, and the controller and the communicator receiving the output voltage of the converter, and in the power supply route C the power supply and the converter being connected to each other, the output of the converter being supplied to the controller and the communicator, the first sensor unit being not electrically conducted to the power supply, the converter being connected to the power supply, the regulator being not connected to the output of the converter, and the controller and the communicator receiving the output voltage of the converter.