PURPOSE: To dispense with a die for forming a shielding material, to facilitate changing the shape and position of a window, and to enable the width of the window smaller, by providing a shielding member formed by depositing shielding material in a preset thickness thereto on the surface of a translucent resin.

CONSTITUTION: In the case of a reflective photo interrupter, a light emitting device 1 and a light receiving device 2 are mounted on the same lead frame 4 and internally connected via gold line 5. And when it is completed as a finished product, a lead frame 9 for connection is provided to prevent a mold body on the light emitting side from separating from a mold body on the light receiving side. After this is molded in a translucent resin 3, it is coated by a shielding member 10 which is a shielding type paint or metal. If the shielding member 10 is the paint, a method of spraying, printing, dropping or dipping it into the paint can be considered. Also, if it is the metal, it can be formed by vacuum evaporation or plating.