PURPOSE: To make it possible to form a thermosetting resin film onto the outer surface of a thermoplastic resin molded item with no remarkable delay in the injection molding cycle by a method wherein a thermosetting composition, to which peroxide is added so as to prevent the radical in a coat from being inactivated by the oxygen in the air, is applied onto a heated mold and, after that, molten resin is injected in the mold.

CONSTITUTION: A composition, which is prepared by mixing, for example, pentaerythritol triacrylate, triethylen oxide diacrylate, benzoyl peroxide and silicon-based leveling agent with one another, is applied with a spray gun onto the cavity part, which allows to mold a plate-shaped molded item and is heated at a temperature of 90°C, of an injection mold and left under the state that the air in the cavity part of the mold is displaced with nitrogen gas. The resultant coat is hardened under the state mentioned above. Next, polycarbonate melted at 290°C is injected in the mold and a molded item is removed from the mold after cooling. A thermoset acrylate film is fully and integrally formed onto the outer surface of the polycarbonate molded item.