An interference wave detecting apparatus includes a first Fourier transformer for frequency-converting a received signal; an extractor for extracting a known information signal from the frequency-converted received signal; an interpolator for performing interpolation to the known information signal in frequency domain, generating a first transmission path estimation signal as a frequency-domain information signal; an inverse Fourier transformer for inverse-Fourier-transforming the known information signal, generating a time-domain information signal; a waveform shaping section for shaping a waveform of the time-domain information signal; a second Fourier transformer for Fourier-transforming the shaped time-domain information signal, generating a second transmission path estimation signal as a frequency-domain information signal; and a comparing-computing section for comparing the first and second transmission path estimation signals, generating an interference wave detection result which indicates a ratio of an interference wave of the received signal.