Disclosed is a plasma processing method. The method includes forming a protective film on an inner wall surface of a processing container of a plasma processing apparatus; and executing a processing on a workpiece within the processing container. When forming the protective film, a protective film forming gas is supplied from an upper side of the space between the mounting table and the side wall of the processing container so that plasma is generated. When executing the processing, a workpiece processing gas is supplied from an upper side of the mounting table so that plasma is generated.