Plasma processing apparatus

A plasma processing apparatus comprising:

• a plasma processing chamber;
• an electrical member disposed in the plasma processing chamber;
• an electrical circuit electrically connected to the electrical member;
• and
• a filter device electrically connected between the electrical member and the electrical circuit, the filter device including;
• a coil wound around an axial direction,
• a plurality of movable members attached to the coil, each of the plurality of movable members being individually movable along the axial direction, and
• a cylindrical conductor surrounding the coil and the plurality of movable members.

A filter device for use in a plasma processing apparatus comprising:

• a coil wound around an axial direction, the coil having a plurality of turns;
• a plurality of movable member groups corresponding to the plurality of turns, respectively, each of the movable member groups including a plurality of movable members attached to the corresponding turn of the coil and individually movable along the axial direction;
• and
• a cylindrical conductor surrounding the coil and the plurality of movable member groups.