The invention provides a plasma processing apparatus capable of preventing the production of particle and preventing the influence of particle on the sample. The plasma processing apparatus comprises a vacuum chamber; process gas introducing means for introducing process gas into the vacuum chamber; means, coupled to a first RF power supply, for applying RF energy to the process gas introduced into the vacuum chamber to turn the process gas into plasma; a sample mounting electrode for mounting a sample on an upper surface thereof and holding the sample in the vacuum chamber; evacuation means for evacuating the process gas in the vacuum chamber; and plasma confining means, provided on a peripheral side of the mounting electrode in the vacuum chamber, for inflecting flow of the process gas caused by the evacuation means on a downstream side of a sample mounting surface of the mounting electrode to prevent plasma from diffusing downstream of the sample mounting surface.