Abstract: An electrode pattern forming method comprising the steps of: forming a transparent conductive film on a substrate, covering said transparent conductive film with an aluminum film, forming a resist material film for etching on said aluminum film, exposing said resist material film followed by developing by immersing said substrate in an electrolyte to form a resist pattern, and patterning said aluminum film using said resist pattern as a mask;the formation of said resist pattern in said electrolyte being conducted with another transparent conductive film which is in direct contact with said electrolyte and electrically connected to said aluminum film.