A method of manufacturing an organic light emitting display device, including: forming a first film of an organic material, and having first and second surfaces facing each other and a third surface perpendicular to the first and second surfaces; forming a second film on the first film to cover the second and third surfaces of the first film; forming an organic light emitting unit on the second film; forming a third film on the second film to cover the organic light emitting unit; forming a fourth film of an organic material on the third film and having fourth and fifth surfaces facing each other and the fifth surface facing the third film; combining the second support substrate and the first support substrate such that the fifth surface faces the third film; detaching the second support substrate from the fourth surface; and detaching the first support substrate from the first surface.