A method of producing a patterned birefringent product, comprising at least steps [1] to [3] in this order: [1] producing a birefringent pattern building material comprising at least one optically anisotropic layer, which is formed by a process including: coating and drying a composition containing at least one rod-like liquid crystalline compound having at least two reactive groups and at least one chiral agent to form a cholesteric liquid crystal phase; and then subjecting the cholesteric liquid crystal phase to heating or exposure to radiation to form the optically anisotropic layer containing a polymer fixed by polymerization and fixing; [2] subjecting the birefringent pattern building material to a patterned exposure to light; and, [3] baking a laminate obtained after the step [2] at 50° C. or higher and 400° C. or lower.