Disclosed is an etching method for selectively etching an oxidation layer made of silicon from a processing target object having the oxidation layer within a processing chamber of a plasma processing apparatus. The etching method includes: forming an altered layer by generating plasma of a gas containing hydrogen, nitrogen, and fluorine to alter the oxidation layer; and after the forming the altered layer, irradiating secondary electrons to the processing target object to remove the altered layer within the processing chamber, in which a negative direct current voltage is applied on an upper electrode of the plasma processing apparatus so that positive ions generated from plasma collide against the upper electrode and thus the secondary electrons are emitted from the upper electrode.