A plasma processing apparatus includes a processing chamber, a first radio frequency power supply for outputting a first radio frequency power, the first radio frequency power supply being electrically connected to a first electrode arranged in the processing chamber, a heater power supply for supplying electric power to a heating element provided in the first electrode, first and second power supply lines for electrically interconnecting the heating element and the heater power supply, and a filter circuit provided in the first and second power supply lines for attenuating radio frequency noises coming from the heating element. The filter circuit includes a first and a second air-core coil respectively provided on the first and the second power supply line at an initial stage of the filter circuit when viewed from the heating element, the air-core coils being in a coaxial relationship with each other and having substantially the same winding length.