An A/D conversion circuit includes: an input capacitance to which an input signal and a reference signal are sequentially applied; an operational amplifier; a first switch connected between the other end of the input capacitance and a first input end of the operational amplifier; a feedback capacitance connected to the first input end of the operational amplifier; a second switch connected between the other end of the feedback capacitance and an output end of the operational amplifier; a third switch selectively applying a predetermined voltage to the other end of the feedback capacitance; a fourth switch selectively causing a short circuit between the first input end and the output end of the operational amplifier; a fifth switch applying the predetermined voltage to a second input end of the operational amplifier; and a sixth switch applying a ramp reference voltage to the second input end of the operational amplifier.