Abstract: A flexible printed-circuit board covered with a coverlay is produced by bonding (a) a flexible printed-circuit board that comprises a flexible base having a surface bearing a circuit and (b) a polyimide film having a surface treated to increase adhering property and another surface not treated to increase adhering property, each of the surfaces being coated with an adhesive layer, with the adhesive layer on the surface treated to increase adhering property interposed between the polyimide film and the surface bearing the circuit, and then peeling off the adhesive layer coating the polyimide film on the surface not treated to increase adhering property.