An orthogonal frequency division multiplexing (OFDM) demodulator demodulates an OFDM signal constituted by OFDM symbols each including at least an effective symbol and a scattered known signal. The OFDM demodulator includes a Fourier transform performing unit, a known signal extracting unit, a time dimension interpolation unit, a delay spread generating unit, a frequency dimension interpolation unit, and a waveform equalizing unit. The delay spread generating unit employs a time difference between a time point for a starting position of the Fourier transform operation performed by the Fourier transform performing unit and a time point at which a latest arriving path arrived as the delay spread.