A plasma processing apparatus for performing a plasma process on a target substrate includes a process container configured to accommodate the target substrate and to reduce pressure therein. A first electrode is disposed within the process container. A supply system is configured to supply a process gas into the process container. An electric field formation system is configured to form an RF electric field within the process container so as to generate plasma of the process gas. A number of protrusions are discretely disposed on a main surface of the first electrode and protrude toward a space where the plasma is generated.