An AD converter that operates at high speed and precision of which is disclosed. The AD converter includes an analog-to-digital (AD) conversion part that samples an analog signal according to a sampling clock and converts it into a digital signal, a jitter measuring circuit that measures the jitter of the sampling clock, and a correction circuit that corrects a digital signal output from the AD conversion part. The AD converter further comprises a clock source and a sampling generating circuit that generates a sampling clock by dividing the clock generated by the clock source, wherein the jitter measuring circuit measures the jitter of the sampling clock with respect to the click on the basis of a clock CK.