Patent ID: 7112926

Claim:
A matching unit, provided between a high frequency power supply and a high frequency load introducing part, for matching an impedance of a high frequency load with a transmission path impedance, said matching unit comprising: a resonance rod for transmitting a high frequency energy from a high frequency power supply to a high frequency load introducing part; a variable capacitor, connected to said resonance rod and said high frequency load introducing part in series, for adjusting an imaginary part of an impedance complex number; a housing which is provided outside of said resonance rod and which is grounded; and a variable coupling feeding part for exciting a high frequency energy to said resonance rod and for adjusting a real part of the impedance complex number, wherein said variable capacitor and said variable coupling feeding part are adjusted so that a series resonance circuit is formed between said high frequency power supply and said high frequency load in a state that the impedance of said high frequency load is matched with the transmission path impedance.