Plasma processing apparatus and shower head

A plasma processing apparatus comprising:

• a shower head that is installed within a processing chamber for processing a substrate therein and faces a mounting table for mounting thereon the substrate, the shower head being configured to supply a gas toward the substrate in a shower pattern through a plurality of gas discharge holes provided in a facing surface of the shower head facing the mounting table;
• a plurality of gas exhaust holes formed through the shower head to be extended from the facing surface of the shower head to an opposite surface to the facing surface;
• a plurality of openable and closable trigger holes that is formed through the shower head to be extended from the facing surface of the shower head to the opposite surface, and is configured to allow plasma leakage from the facing surface to the opposite surface;
• and
• a partition wall installed in a gas exhaust space provided on the side of the opposite surface of the shower head to divide the gas exhaust space into a plurality of regions, each region communicating with one or more trigger holes.