A receiving apparatus comprises a first waveform degradation compensating unit, a second waveform degradation compensating unit, a received waveform measuring unit for measuring waveform data on a received signal, a control unit for controlling compensation characteristics of the first and second waveform degradation compensating units to minimize a difference between frequency data obtained by converting the obtained received waveform data into a frequency domain and frequency data on a reference waveform free from waveform degradation, and time-constant generating units for making a difference in compensation characteristic control speed between the first and second waveform degradation compensating units. This realizes high-accuracy compensation for waveform degradation of a received signal stemming from chromatic dispersion, polarization mode dispersion or the like without employing a dispersion compensation fiber or a polarization maintaining fiber.