In a plasma processing method which comprises supplying a processing gas to a
vacuum vessel forming a plasma production part, producing a plasma using an antenna
and a Faraday shield which are provided at outer periphery of the vacuum vessel
and to which a high-frequency electric power can be applied, and carrying out the
processing, a voltage of at least 500 V is applied to the Faraday shield and a
sample which is disposed in the vacuum vessel and which is a nonvolatile material
as a material to be etched is etched.
