A method of forming a thin film, the method including: disposing a resist portion on a substrate, the resist portion including: a first region including a first upper surface; and a second region including a second upper surface, the first upper surface disposed higher than the second upper surface and forming a step; disposing a first protection layer covering the resist portion; exposing the first upper surface; removing the first region; disposing a first thin film on the substrate; disposing a second protection layer covering the first thin film; exposing the second upper surface; removing the second region; disposing a second thin film on the substrate; and removing the first protection layer and the second protection layer.