An inorganic film is dry-etched using plasma with a photoresist pattern serving as a mask, and an organic film is dry-etched using plasma with the photoresist pattern serving as a mask without exposing a pad electrode. The photoresist pattern is removed using a stripping solution. After the removal of the photoresist pattern using a stripping solution, the organic film is etched to expose the pad electrode with the inorganic film that remains after the dry etching of the inorganic film using plasma serving as a mask.