A method for molding an in-mold coating product including a substrate and a coating formed on a surface of the substrate. A first mold including a fixed mold piece is closed to form a substrate cavity therein. The substrate cavity is charged with a resin to form the substrate with a seal projection formed near the parting line of the first mold. Then, a second mold, which uses the fixed mold piece of the first mold, is closed with the substrate arranged on the fixed mold piece to form a coating cavity therein. The second mold deforms the seal projection so that when a coating material is charged into the coating cavity, the coating material does not leak out toward the parting line of the second mold.