Metal and plastic can be bonded in a single process by metal insert molding, in which a metal is inserted into a mold and a plastic resin is then injected. In this study, adhesion strengths for metal insert molded specimens have been investigated with variously surface treated metal plates. A laser machining, etching, and sand blasting were used for an engraving surface treatment and a plating process was performed for an embossed surface treatment of the metal. Particles such as glass beads, ceramic beads, artificial diamonds, and aluminum oxides were employed in the plating process. The adhesive strength significantly increased when an undercut shape was formed at the metal surface. The best adhesive strength with polymers was found in the metal specimen plated using aluminum oxide particles.