Plasma processing method and etching apparatus

A plasma processing method comprising:

• a first processing step of arranging a wafer to be processed in a processing chamber, supplying plasma of an organic gas containing fluorine into the processing chamber, depositing a fluorocarbon layer over the upper surface of a film layer to be processed that is formed over the upper surface of the wafer beforehand and contains tungsten, and forming an intermediate layer that contains tungsten and fluorine in the film layer to be processed and is self-limiting between the fluorocarbon layer and the film layer to be processed;
• and
• a second processing step of supplying particles in plasma formed in the processing chamber by using a gas containing oxygen to the upper surface of the film layer to be processed and removing the fluorocarbon layer and the intermediate layer.