A plasma processing apparatus according to the present invention includes a processing chamber, a first radio frequency power source, and a second radio frequency power source. The first radio frequency power source supplies radio frequency power to generate the plasma. The second radio frequency power source applies a first radio frequency voltage to a sample stage. The plasma processing apparatus further includes a third radio frequency power source and a control unit. The third radio frequency power source applies, to the sample stage, a second radio frequency voltage having a frequency which is N times a frequency of the first radio frequency voltage in a case where N is a natural number of 2 or more. The control unit controls a phase difference such that the phase difference between a phase of the first radio frequency voltage and a phase of the second radio frequency voltage reaches a predetermined value.