To provide a high-speed and small-sized analog/digital (A/D) converter.

An A/D converter is provided which includes a high-order bit comparator (112), a plurality of amplifiers (103), a plurality of second selectors (104), a plurality of low-order bit comparators (109) and a third selector (110). The high-order bit comparator (112) divides a plurality of reference voltages into a plurality of areas and compares an input analog voltage with an area boundary voltage in order to determine the area, to which the input analog voltage belongs, from among the plurality of divided areas. The plurality of amplifiers (103) output differential voltages between the plurality of reference voltages and the input analog voltage. The plurality of second selectors (104) select output signals of the amplifiers in accordance with the area determined by the high-order bit comparator from among the output signals of the amplifiers as many as the number of the plurality of divided areas. Each of the plurality of low-order bit comparators (109) compares magnitudes of two of the signals selected by the plurality of second selectors and outputs a comparison result signal. The third selector (110) selects any one of output signals of the low-order bit comparators.