A retardation substrate is provided, which includes a substrate and an optically anisotropic solidified liquid crystal layer which is supported by the substrate and formed as a continuous film made from a same material. The solidified liquid crystal layer comprises first to third regions each having two sub-regions which are a sub-region A and a sub-region B, an in-plane birefringence of the 1A sub-region is larger than that of the 2A sub-region, the in-plane birefringence of the 3A sub-region is smaller than that of the 2A sub-region, and an in-plane birefringence of the 1B sub-region is the same as that of the 3B sub-region, smaller than that of the 1A sub-region and larger than that of the 3A sub-region.