IMPEDANCE ADJUSTMENT DEVICE

PROBLEM TO BE SOLVED: To solve the problem wherein impedance matching using a characteristic parameter indicating a transmission characteristic of an entire impedance adjustment device cannot be performed if a variable frequency type high frequency power supply 1v is used.SOLUTION: An impedance adjustment device 3A is applied to a high frequency power supply system using the variable frequency type high frequency power supply 1v. A characteristic parameter covering part of combination information of position information C about a variable capacitor 21 and output frequency information F about the high frequency power supply 1v is stored in a memory 70. A T parameter acquisition section 130 acquires the characteristic parameter corresponding to current (Cnow,Fnow). An output reflection coefficient computation section 140 computes a reflection coefficient outnow of an output end. An imaginary output reflection coefficient computation section 160 computes a reflection coefficient outnow'(C,F) at an imaginary output end. An approximate reflection coefficient search section 180 provides impedance matching on the basis of a reflection coefficient outnow"(C,F) closest to the reflection coefficient outnow.