The voltage comparison apparatus of the invention features a timing control of clocks by which individual switches are ON/OFF controlled so that before a preceding amplifier circuit goes into comparison mode from auto zero mode, a successive amplifier circuit may go into auto zero mode from comparison mode, or before the preceding amplifier circuit goes into auto zero mode from comparison mode, the successive amplifier circuit may go into comparison mode from auto zero mode, whereby before the preceding amplifier circuit undergoes transition from the auto zero mode to the comparison mode, the successive amplifier circuit goes into the auto zero mode from the comparison mode, or before the preceding amplifier circuit undergoes transition from the comparison mode to the auto zero mode, the successive amplifier circuit goes into the comparison mode from the auto zero mode, and even when considerable variation occurs in input voltage difference during each clock cycle or clock time lags occurs, stable operation can be assured.