In a plasma processing apparatus, a connector section with the film-like electrode of a sintered plate of a sample stage to which high-frequency power is supplied includes a conductor section disposed inside a through hole, an upper part of which is bonded to the film-like electrode and a lower part of which is connected to an end of a power supply path of the high-frequency power, and a boss disposed between the conductor section and a substrate surrounding an outer periphery of the conductor section inside the through hole and made of an insulating material. Upper ends of a rod-like member at the center of the conductor section and a socket surrounding the rod-like member are disposed at a position higher than the boss, and an adhesive is prevented from entering between the socket and the rod-like member in the upper end of the socket.