To provide the DC component-removing device, which can decrease the effect of sudden noises on digital operation.

A DC component-removing device 1 has the following parts. Sampling circuits 4 and 5 sample at least one period of AC signals at a specified time interval. An A/D converter circuit 6 performs the digital-analog conversion of the sampled AC signal. An operating part 7 operates the average signals based on a plurality of reference digital data, which have undergone digital conversion, and operates a plurality of new digital data obtained by removing the DC component from the AC signal based on the average value and a plurality of the reference digital data. In this DC component-removing device 1, the operating part 7 operates the moving average value data in respective correspondence with each of a plurality of the reference digital data by a moving average method and operates a plurality of the new digital data by subtracting the average value from each of the moving average value data.