A sensor circuit has: a sensor portion that obtains, as an electrical signal, information on an object to be measured or detected; and a control circuit that controls the operation of the sensor portion. The control circuit receives a start input signal inputted thereto from outside for making the sensor portion operate only for a given duration after the start input signal is inputted thereto. With this configuration, it is possible to reduce the current consumption by arbitrarily controlling a period of an intermittent operation of the sensor circuit.