A retardation layer having multiple regions having different retardation values can be produced readily. A retardation substrate (10) comprises a substrate (110) and a solidified liquid crystal layer (130) supported on the substrate (110). The solidified liquid crystal layer (130) has first to third regions (130a, 130b, 130c). The first to third regions (130a, 130b, 130c) are arranged in rows on the substrate (10) and have different degrees of orientation of a mesogen from one another.