Plasma processing device

A plasma processing apparatus, comprising:

• a processing vessel defined by an outer wall and having a stage for holding a substrate to be processed;
• an evacuation system coupled to said processing vessel;
• a plasma gas supply part for supplying plasma gas to an interior of said processing vessel;
• a microwave antenna provided on said processing vessel;
• and
• a process gas supply part provided between said substrate to be processed on said stage and said plasma gas supply part so as to face said substrate to be processed on said stage,
• wherein said process gas supply part comprises:
• a first component comprising a plurality of first apertures configured to provide flow communication for passing plasma formed in the interior of said processing vessel, a process gas passage capable of connecting to a process gas source, and a plurality of second apertures in flow communication with said process gas passage;
• and
• a second component comprising a plurality of third apertures corresponding to and being in substantially axial alignment with said first apertures of said first component and a plurality of diffusion surfaces upon recessed areas of said second component positioned opposite to said second apertures in said first component.