An A/D conversion circuit includes a plurality of transmission paths that transmit signal voltages and reference voltages, and an A/D conversion unit that A/D converts voltages output from the transmission paths. Each of the plurality of transmission paths includes a first switch that selectively outputs one of the signal voltage and the reference voltage, an S/H circuit that holds output voltage from the first switch, and a second switch that selectively outputs one of the output voltage from the first switch and output voltage from the S/H circuit.