A filter coefficient group computation device is configured from a means for performing inverse Fourier transform on a frequency characteristic inputted through an input means; a means for performing short-term Fourier transform on a numerical string obtained by the inverse Fourier transform; a means for performing windowing on a frequency domain signal, obtained by the short-term Fourier transform, using a function of which a window length shortens as frequency increases; a means for performing short-term inverse Fourier transform on the frequency domain signal after the windowing; a means for performing overlap addition on a numerical string obtained by the short-term inverse Fourier transform; and a means for determining a numerical string after the overlap addition as a filter coefficient group which forms a filter having the frequency characteristic inputted through the input means.