Plasma processing apparatus

A plasma processing apparatus, comprising:

• a chamber being possible to maintain an atmosphere more depressurized than atmospheric pressure;
• a plasma generator generating a plasma inside the chamber;
• a gas supplier supplying a gas into the chamber;
• a placement part, the placement part being positioned below a region where the plasma is generated, a processed product being placed on the placement part;
• a depressurization part positioned below the placement part, and depressurizing inside of the chamber;
• and
• a supporting part supporting the placement part in an internal space of the chamber,
• the supporting part including
• a mounting part, the mounting part being positioned below the placement part and being provided with the placement part,
• a beam extending from a side surface of the chamber toward a center axis of the chamber inside the chamber, one end of the beam being connected to a side surface of the mounting part, a main space being included inside the beam, the main space being connected to an outside space of the chamber,
• a thickness of a side portion on the placement part side of side portions of the beam is t1, the placement part side of side portions of the beam is from a top of the main space to a top of the beam, t1 is 14 mm to 18 mm,
• a thickness of a side portion on an opposite side of the placement part side of the beam is t2, the opposite side of the placement part side of the beam is from a bottom of the main space to a bottom of the beam, t2 is 8 mm to 10 mm,
• a distance between an outer wall of the chamber and the center axis of the chamber is L, L is 260 to 350 mm,
• a weight of the placement part is W, W is 56 to 70 kgf (weight kilogram).