| abstract |
A film which is a single polymer film and has a smaller phase difference as the wavelength becomes shorter. This film is made from an olefin-based polymer which has an alicyclic group in the side chain, such as hydrogenated polystyrene, the amount of the alicyclic group in the side chain being 60 to 90 wt % based on the whole polymer, and satisfies the following expression: n R (450)/ R (550)<1 n wherein R(450) and R(550) are phase differences on the film plane at a wavelength of 450 nm and a wavelength of 550 nm, respectively. |