A retardation film comprised of a single oriented polymer film, characterized in that the retardation at wavelengths of 450 nm and 550 nm satisfies the following formulae (1) and/or (2), and the water absorption is no greater than 1%. R(450)/R(550)<1 (1) K(450)/K(550)<1 (2) where R(450) and R(550) represent the in-plane retardation of the oriented polymer film at wavelengths of 450 nm and 550 nm, respectively, and K(450) and K(550) are the values calculated by K=[n.sub.z -(n.sub.x +n.sub.y)/2].times.d (where n.sub.x, n.sub.y and n.sub.z represent the three-dimensional refractive indexes of the oriented polymer film as the refractive indexes in the direction of the x-axis, y-axis and z-axis, respectively, and d represents the thickness of the film) for the oriented polymer film at a wavelength of 450 nm and 550 nm, respectively. There are provided laminated retardation films and liquid crystal display devices employing the retardation film.

Uma película do retardation compreendida de uma única película orientada do polímero, caracterizado naquele o retardation em wavelengths de 450 nm e de 550 nm satisf às seguintes fórmulas (1) e/ou (2), e o absorption da água é não mais grande de 1%. R(450)/R(550)