To enhance adhesiveness of a substrate including a lactone ring-containing polymer with a functional layer.

A method of producing a laminated body includes a coating step of coating the substrate 4 with a coating composition for forming the functional layer 6, and a drying step of drying the coated composition. In the coating step and/or drying step of this method, the substrate 4 is impregnated with the coating composition. The laminated body 2 is provided with the substrate 4 and the functional layer 6 in contact therewith. The substrate 4 includes a thermoplastic resin (L) comprising the lactone ring-containing polymer as a main component. The functional layer 6 is impregnated into the substrate 4. Preferably, the substrate 4 is stretched.