Abstract: A photo-reflective sensor comprising a light-emitting element and a light-detecting element adapted to receive the light from the light-emitting element after the light has been reflected from an article to be detected as modulated by a variation in the reflectance of the article. The sensor is characterized in that it is fabricated by molding a light-blocking wall portion, an outer case portion and a lead wire fixing portion integrally from an insulating base material to form a header, fixing chip lead wires and internal wiring lead wires to the header to form a stem, placing a photo-emitting chip and a photo-detecting chip on the chip lead wires and connecting the chips to the internal wiring lead wires to form the light-emitting and light-detecting elements. The sensor can be manufactured in a small size, by a reduced number of assembly steps and with improved light-blocking characteristics.