A plasma treatment apparatus has a reaction vessel (11) provided with a top electrode (13) and a bottom electrode (14), and the first electrode is supplied with a VHF band high frequency power from a VHF band high frequency power source (32), while the bottom electrode on which a substrate (12) is loaded and is moved by a vertical movement mechanism. The plasma treatment system has a controller (36) which, at the time of a cleaning process after forming a film on the substrate (12), controls a vertical movement mechanism to move the bottom electrode to narrow the gap between the top electrode and bottom electrode and form a narrow space and starts cleaning by a predetermined high density plasma in that narrow space. In the cleaning process, step cleaning is performed. Due to this, the efficiency of utilization of the cleaning gas is increased, the amount of exhaust gas is cut, and the cleaning speed is raised. Further, the amount of the process gas used is cut and the process cost is reduced.