A plasma processing apparatus includes a vacuum evacuable processing chamber; a first electrode for supporting a substrate to be processed in the processing chamber; a processing gas supply unit for supplying a processing gas into a processing space; a plasma excitation unit for generating a plasma by exciting the processing gas in the processing chamber; a first radio frequency power supply unit for supplying a first radio frequency power to the first electrode to attract ions in the plasma to the substrate; and a first radio frequency power amplitude modulation unit for modulating an amplitude of the first radio frequency power at a predetermined interval. The plasma processing apparatus further includes a first radio frequency power frequency modulation unit for modulating a frequency of the first radio frequency power in substantially synchronously with the amplitude modulation of the first radio frequency power.