Plasma processing apparatus and plasma processing method

The reliability of a plasma processing apparatus can be improved, and the yield of plasma processing can be improved. A plasma etching apparatus 100 has a susceptor ring 113 covering the surface of a sample stage, a conductor ring 131 disposed in the interior of the susceptor ring 113 and to which second high frequency electric power is supplied from a second high frequency power source, and an electric power supply connector 161 configuring a path for supplying the second high frequency electric power to the conductor ring 131. Further, the electric power supply connector 161 includes a plate spring 135 disposed in the interior of an insulating boss 144 disposed in a through hole 120c of the sample stage and having resiliency in such a manner that the plate spring 135 is connected to an upper terminal 143 and a lower terminal 145, is biased in an up-down direction P, and is expanded and contracted.