A method for forming a three-dimensional structure made of a photosensitive material on a substrate includes the steps of determining a film thickness of the photosensitive material necessary to form the desired three-dimensional structure, comparing a predetermined maximum film thickness with the film thickness determined by the determining step, and applying, when the film thickness determined by the determining step is greater than the predetermined maximum film thickness, the photosensitive material within the maximum film thickness plural times until the photosensitive material has the film thickness on the substrate.