Patent ID: 7908104

Claim:
A plasma processing apparatus having a vacuum processing chamber and a plasma generating means for generating plasma in the vacuum processing chamber for subjecting a sample placed in the vacuum processing chamber to plasma processing, comprising: a frequency spectrum measurement means for measuring the frequency spectrum of a reflected power of an electromagnetic wave reflected from the vacuum processing chamber, wherein the frequency spectrum measurement means includes: an electromagnetic wave generating means for generating a frequency-swept electromagnetic wave having weak power so as not to cause plasma discharge in the vacuum processing chamber; an electromagnetic wave supplying means for supplying the electromagnetic wave from the electromagnetic wave generating means into the vacuum processing chamber having no plasma generated therein; and a reflected power detecting means for detecting the frequency spectrum of reflected power of the electromagnetic wave reflected from the vacuum processing chamber; wherein the frequency spectrum measurement means comprises: a storage means for storing a frequency spectrum pattern of the reflected power measured in advance by the frequency spectrum measurement means for reflected power as a reference of the change in status of the plasma processing apparatus unique to the plasma processing apparatus; a determination means for determining defect of the plasma processing apparatus based on the difference between the reference and the newly-measured frequency spectrum pattern of the reflected power; and a display means for displaying the result determined by the determination means.