Provided is a magnetic sensor circuit capable of a low-voltage operation, which comprises a Hall element and a magnetic offset cancellation circuit for the Hall element. In the magnetic sensor circuit using the Hall element, at the time of turning on transmission gates for switching connections between input terminals of an amplifier circuit in the magnetic offset cancellation circuit and electrodes of the Hall element in order to cancel a magnetic offset of the Hall element, gates of N-channel transistors in the transmission gates are set at voltages higher than a power supply voltage by a drive circuit.