To remove an unwanted component caused by bit width rounding processing.

A wanted component removing circuit is equipped with:a frequency shift processing section 12 which shifts an effective band of an LPF 11 limiting the frequency band of a digital signal to move the effective band outside a center frequency C of the LPF; and a frequency shift processing section 14 which, after bit width rounding processing is implemented for an output signal of the LPF 11 of which the effective band is moved outside the center frequency C by the frequency shift processing section 12, shifts a frequency band of the output signal inversely to effective band shifting performed by the frequency shift processing section 12, and matches a center frequency of the frequency band of the output signal to the center frequency C.