The invention relates primarily to a retardation film and a process for producing the retardation film, wherein a layer formed of a mixture of a photosensitive polymer and a low molecular weight compound is irradiated with linear polarized ultraviolet ray, ultraviolet ray including a perfectly polarized light component and a non-polarized light component, or a non-polarized ultraviolet ray to orient molecules thereby developing a retardation and the direction of the optical axis arbitrarily in the layer formed of a mixture.