PURPOSE: To produce an engineering plastic/silicone rubber composite improved in bonding properties in an extremely efficient manner by continuously subjecting engineering plastic and an addition reaction curable liquid silicone rubber composition to injection molding in succession.

CONSTITUTION: Engineering plastic 7 is primarily injected in the cavity of a mold to be cooled to the glass transition temp. thereof or higher. Subsequently, an addition reaction curable liquid silicone rubber composition 8 is primarily injected in the cavity to be bonded and cured at 80-130°C. By this method, it is unnecessary to physically treat the surface of the engineering plastic subjected to injection molding previously in order to improve adhesiveness. Therefore, an engineering plastic/silicone rubber composite can be efficiently produced and the adhesiveness of both of them can be also improved.