An electronic circuit, which has transistors disposed on a substrate, each transistor including an active layer made of thin-film polysilicon, includes a sensor that converts a measured quantity into a current value, a current-voltage conversion circuit that converts the current value into a voltage, and a voltage detection circuit that detects the voltage converted by the current-voltage conversion circuit and outputs a predetermined signal. The current-voltage conversion circuit includes a storage circuit and a range-switching circuit that switches a current-voltage conversion range of the current-voltage conversion circuit by switching the capacitance of the storage circuit.