A polymer film that has an in-plane retardation Re(λ) and a thickness-direction retardation Rth(λ) satisfying formula (i) and (ii), and that further has a surface energy of at least one surface is from 50 mN/m to 80 mN/m: 0≦Re(630)≦10, and |Rth(630)|≦25;  (i) and |Re(400)−Re(700)|≦10, and |Rth(400)−Rth(700)|≦35.  (ii) in the formulae, Re(λ) and Rth(λ) are measurement values at the wavelength of λ nm, and an optically-compensatory film, an optical material such as a polarizer and a liquid-crystal display device using the polymer film.