PLASMA TREATING APPARATUS

PROBLEM TO BE SOLVED: To prevent the dust generated at the time of operation of an apparatus from exerting an adverse influence on a plasma treatment by disposing a preliminary chamber between a plasma chamber and a gas supplying means or in the plasma chamber and providing the preliminary chamber with a gas supplying means in such a manner that gas is impulsively supplied from the preliminary chamber to the plasma chamber. SOLUTION: A plasma chamber 2 is provided with the preliminary chamber 100. A pulse gas valve 8 is mounted at the end face of the preliminary chamber 100. The gas supplied from the pulse gas valve 8 is supplied through the preliminary chamber 100 to a process chamber 1. When the pulse gas valve 8 is operated, the dust, such as splinters of the component members thereof, is moved downward by gravity and deposit or adhere on or to the rear surface of the preliminary chamber 100 and, thereafter, the does not infiltrate the process chamber 1 any more. The polymerized films peeled after adhering to the pulse gas valve 8 in the process using the etching gas having a high CVD or deposition characteristic adhere to the rear surface of the preliminary chamber 100 and do not infiltrate the process chamber 1 any more.