Dry etching by alternately etching and depositing

A dry etching method comprising the steps of:

• alternately introducing an etching gas and a deposition gas into a reaction chamber at predetermined time intervals;
• and
• alternately etching an exposed surface of an article to be etched and causing a film to be deposited on said surface of said article by applying a first power to said introduced etching and deposition gases to alternately generate an etching plasma and deposition plasma, said etching and deposition plasma alternately coming into contact with said article to be etched said reaction chamber in order to alternately etch and cause a film to be deposited on said surface so as to etch said surface, and said first power being applied after passage of a predetermined amount of time from the start passage of a predetermined amount of time from the start of the introduction of said deposition gas and before the introduction of said etching gas and cut off when the introduction of said etching gas is suspended;
• and
• applying a second power to said article to be etched when the introduction of said etching gas is started and cutting off said second power at a time prior to suspension of the introduction of said etching gas.