PLASMA PROCESSING METHOD

PROBLEM TO BE SOLVED: To provide a plasma processing method capable of stably holding a processing shape.SOLUTION: The plasma processing method is used to perform plasma processing to a wafer carried into a vacuum processing reactor through the use of an apparatus comprising a vacuum processing chamber, a gas supply apparatus, plasma generating means for generating plasma, an emission spectroscope for monitoring plasma emission, and a device for storing emission spectrum. In the plasma processing method, a non-operating time of the apparatus (idling SS) occurs causing the mass production processing of the wafer to be temporarily stopped. Emission intensities SiF(1) and SiF(2) in the plasma including the information on the state of deposition of reaction products and the temperature on the uppermost surface of the reactor are monitored during cleaning steps S2 and S2' before and after the idling SS, and a database S4 is referenced on the basis of these emission spectrums, so that the time of the plasma heating step S3 after the idling SS is controlled to heat the reactor, and after performing plasma heating S3, the next sample is subjected to etching S2.