PURPOSE: To form constinuously, quickly and highly reliably reflecting films having stable film quality into a large quantity by connecting a substrate holding the outside circumferential part of a disc and a disc holding the inside circumferential part by means of plural connecting bars and subjecting the disc to vapor deposition from the side of the connecting bars.

CONSTITUTION: A substrate 11 is provided with a part 12 holding the outside circumferential part of a disc provided with a notch and a disc 13 holding the inside circumferential part of the disc. A resin substrate 2 is placed between the same. The substrate 11 and the disc 13 are connected by means of connecting bars 14. When Al is deposited by vacuum evaporation, no deposition is made on the part 12 and the disc 13 and reflection films can be selectively formed. If the distance between the vapor deposition surface of the substrate 2 and the bars 14 is short, the shadows of the connecting bars are produced to prohibit thorough sticking of the reflecting film. The long distance is not adequate for the reduction in the size of the device. The adequate distance between the disc and the connecting bars is ≥5mm. The installation is simple, the disc is easily and quickly attachable and detachable and the method is suitable for mass production.