An analog-to-digital converter includes: a first latch row corresponding to a first stage; a second latch row corresponding to a second stage; and a digital processor for encoding output signals of the second latch row and generating a digital signal. The first latch row includes a plurality of first latches that receive an analog input signal and reference voltages and operate in synchronization with a first clock signal, and the second latch row includes: a plurality of second latches that receive outputs signals of the plurality of first latches and operate in synchronization with a second clock signal delayed from the first reference clock; and a plurality of third latches that receive output signals of two neighboring latches of the plurality of first latches and operate in synchronization with the second clock signal by means of an interpolation technique.