A plasma processing apparatus (11) is provided with: a processing container (12), in which processing is performed using plasma; a plasma generating mechanism (19), which has a high frequency oscillator that oscillates high frequency, includes a high frequency generator that generates high frequency by being disposed outside of the processing container (12), and which generates plasma in the processing container (12) using the high frequency generated by means of the high frequency generator; a determining mechanism, which determines the state of the high frequency oscillator; and a notifying mechanism, which performs notification of determination results obtained from the determining mechanism.