A method of producing a patterned birefringent product, containing at least steps (I) to (III) in this order: (I) providing a birefringent pattern builder having an optically anisotropic layer containing a polymer; (II) subjecting two or more regions of the birefringent pattern builder to exposure to light under exposure conditions different from each other; and (III) heating a laminated structure obtained after the step (II) at 50° C. or higher and 400° C. or lower.