A plasma processing apparatus includes a mounting table including a lower electrode and an electrostatic chuck, a high frequency power supply electrically connected to the lower electrode, a heater provided in the electrostatic chuck, a heater power supply for supplying a power to the heater, a filter unit including a filter connected to the heater power supply, a rod-shaped power feeder connecting the heater power supply and the heater via the filter, an insulating tubular portion having an inner hole through which the power feeder extends, and a conductive choke portion serving to suppress a microwave propagating through the tubular portion. The choke portion includes a first portion extending from the power feeder in a direction intersecting with a longitudinal direction of the power feeder and a cylindrical second portion extending, between the tubular portion and the power feeder, from a peripheral portion of the first portion.