Patent ID: 7993487

Claim:
A plasma processing apparatus which has upper and lower radio-frequency electrodes facing each other in a process vessel and processes a substrate by supplying radio-frequency power to at least one of the radio-frequency electrodes and generating plasma in the process vessel, the apparatus comprising: a probe which is disposed in the process vessel to detect a time varying magnetic flux density directed in a azimuthal direction around an up/down-direction center axis of the process vessel; and a calculation part which calculates an amount of radio-frequency current passing in an axial direction in the plasma when the radio-frequency power is supplied, based on the time varying magnetic flux density detected by said probe, wherein plural ones of said probe are provided at a plurality of positions in the up/down direction in the process vessel, and wherein said calculation part subtracts an amount of the radio-frequency current detected by a probe close to one of the radio-frequency electrodes from an amount of the radio-frequency current detected by the probe close to the other radio-frequency electrode and calculates an amount of the radio-frequency current passing in a radial direction, based on an amount by which the radio-frequency current in the axial direction increases/decreases between said probes.