An optical member (for example, optical fiber) is dipped in a coating solution having a film forming material dissolved therein to form an antireflection film on the end surface of the optical member. When the optical member is pulled up from the coating solution, the angle formed by the level of the coating solution and the end surface of the optical member, or the pulling speed is varied to adjust the film thickness or reflectance of the antireflection film to be formed on the end surface of the optical member. The film forming material is a fluorine-containing compound. The antireflection film is formed by dipping. The film thickness of the antireflection film is uneven.