There are provided a matching unit capable of sufficiently matching the impedance of a high frequency load to a transmission path impedance without increasing its size and matching time even if a high frequency power of 70 MHz or higher is supplied thereto, and a plasma processing system using the same. A matching unit 41 comprises: a resonance rod 61 for transmitting a high frequency energy from a high frequency power supply 40 to a plasma producing electrode; a variable capacitor 62, connected to the resonance rod 61 and an electrode 21 in series, for adjusting the imaginary part of an impedance complex number; a housing 63 which is provided outside of the resonance rod 61 and which is grounded; a link coil 64 for exciting a high frequency energy to the resonance rod 61 and for adjusting the real part of the impedance complex number; and a controller 69 for controlling a driving part for the variable capacitor 62 and the link coil 64 so that a series resonance circuit is formed between the high frequency power supply 40 and the ground via plasma in a matching state.