An insert injection-molded case that provides a better appearance and a reduced defective rate of manufacture can be utilized for a number of products, including but not limited to a cover for portable communication devices. The case preferably includes: a metal plate having one or more fixing portions coupled to fixing members formed in a mold respectively; an injection-molded case body injection molded with the metal plate; and one or more holding portions formed in the injection-molded case body during the injection molding and coupled to the fixing members respectively to prevent deflection of the injection-molded case body caused during a cooling operation after the injection molding.