PURPOSE: To improve an appearance shape by preventing the strain generated between a primary shade and a secondary shade, by providing a groove having a specific shape to the injection port of an injection mold for molding a double shade for illumination in such a state that the secondary shade is superposed onto the primary shade.

CONSTITUTION: Grooves 12 each having a depth slightly larger than the contraction height of a primary shade at the time of molding and cooling are engraved in the above mentioned primary shade along the lower part and outer periphery thereof. By this structure, the molten synthetic resin, which forms a secondary shade 18, introduced under pressure from a material injection port 17 is forcibly flowed to the lower end and side surface of the primary shade 1 while forcibly presses the lower part of the primary shade 1 to the surface of a male mold 2. Therefore, the synthetic resin forming the secondary shade 18 covering the lower end of the primary shade 1 is prevented from turning around to the inside of the primary shade 1. No strain is generated at the boundary 8 between the primary shade 1 and the secondary shade 18.