A lighting unit cover including a deep color (first) resin layer subject to preblanking is laminated and molded in a predetermined position on a backside of a light color (second) resin layer on a surface side subject to postblanking. The second layer protrudes toward the first layer side and a boundary surface between the first and second layers and is offset by a distance toward the first layer side in a laminated portion. The first layer contacts the melted second resin and is subject to postblanking so that a part thereof is molten and drawn by its flow. A step portion in a cavity corresponding to a protruded portion of the second layer toward the first layer side blocks the flow of the molten first resin into the second layer. The first resin is not mixed into the first layer, resulting in excellent appearance and a large light emitting area.