An A/D converter has a first voltage generation circuit, a second voltage generation circuit, a comparator, first and second switch circuits connected in series between an input terminal of an analog input voltage and an output terminal of the first voltage generation circuit, a first capacitor inserted between a connection node between the first and second switch circuits and the first input terminal, a second capacitor inserted between an output terminal of the second voltage generation circuit and the second input terminal, a third switch circuit, a fourth switch circuit, an A/D converter which generates a digital signal in accordance with signal level of the first output terminal, and a voltage setting circuit which sets a voltage to be outputted from the first and second voltage generation circuits based on the digital signal.