Abstract: A plasma processing apparatus includes: a plasma processing chamber; a base support disposed within the plasma processing chamber; a base having a first through hole penetrating from an upper surface of the base to a lower surface of the base and disposed on the base support; an electrostatic chuck having a second through hole communicating with the first through hole by penetrating from a substrate support surface or a ring support surface to a lower surface of the electrostatic chuck and disposed on the base; a first insulating member disposed within the first through hole; a second insulating member disposed within the first through hole to surround at least a portion of the first insulating member; a first sealing member disposed between the first insulating member and the electrostatic chuck; and a second sealing member disposed between the first insulating member and an insulating support member.