Patent ID: 6946847

Claim:
An impedance matching device comprising: an input terminal connect to a high frequency power source; an output terminal connected to a load; a reactance circuit including at least one variable reactor, the circuit arranged between the input terminal and the output terminal; an input detector that detects voltage and current of high frequency power inputted to the input terminal; a matching controller that matches impedance of the power source and impedance of the load by adjusting reactance of the variable reactor based on data detected by the input detector; and an analyzer that analyzes electric characteristics at the output terminal based on both data about the adjusted reactance of the variable reactor and a pre-obtained reactance-impedance data-when the impedance of the power source and the impedance of the load are matched to each other; wherein the reactance-impedance data represents relations between data on a plurality of preselected reactances of the variable reactor and impedance data at the output terminal, the reactance-impedance data being produced with the input terminal connected to the power source or an equivalent of the power source before the output terminal is connected to the load.