In a plasma processing apparatus in which a wafer is processed while supplying radio frequency power to electrodes disposed in a sample stage in a processing chamber within a reactor via a matching box, by matching a specific value of power at transition points of data values of at least two kinds among characteristic data including light emission intensity of the plasma, magnitude of its time variation, a matching position of the matching box, and a change of a value of a voltage of the radio frequency power supplied to the electrodes detected by varying the power to a plurality of values during the processing with a value detected by using characteristic data which is detected during the processing executed on a wafer of the same kind in a different reactor, the differences of the states inside the processing chamber or plasma among a plurality of semiconductor processing apparatuses or reactors are reduced.