In a plasma processing apparatus of an exemplary embodiment, energy of microwaves is introduced from an antenna into the processing container through a dielectric window. The plasma processing apparatus includes a central introducing unit and a peripheral introducing unit. A central introduction port of the central introducing unit injects a gas just below the dielectric window. A plurality of peripheral introduction ports of the peripheral introducing unit injects a gas towards a periphery of the placement region. The central introducing unit is connected to with a plurality of first gas sources including a reactive gas source and a rare gas source through a plurality of first flow rate control units. The peripheral introducing unit is connected to with a plurality of second gas sources including a reactive gas source and a rare gas source through a plurality of second flow rate control units.