Abstract: A method for forming a pattern of metal oxide capable of selectively etching an etching object containing metal oxide relative to a non-etching object and forming a pattern of the metal oxide along a pattern of the non-etching object serving as a template. Metal oxide containing oxide of at least one of tin and indium is etched using an etching gas to form the pattern of the metal oxide. An etching gas containing halon is brought into contact with a member to be etched in the presence of plasma, and etching is performed while a bias power is applied to a lower electrode (2) supporting the member to be etched to selectively etch a metal oxide layer (22) relative to a silicon substrate (24), a template layer (21), and an underlying layer (23), and the predetermined pattern of the template layer (21) is transferred to the metal oxide layer (22).