A plasma processing apparatus includes a first high frequency power for outputting a first high frequency, electrically connected to a first electrode disposed inside a depressurizable processing chamber; a heater power supply electrically connected to a heating element provided in the first electrode via filter circuits for reducing noise of the first high frequency. The plasma processing apparatus further includes air core primary inductors provided in primary stages of the filter circuits when seen from the heating element; and a grounded conductive case for surrounding or accommodating the primary inductors.