A pboto-sensor wherein a bundle of optical fibers is disposed within a predetermined substrate, the optical fiber bundle extending from a first surface to a second surface of the substrate and being formed to be flat, an array of photosensitive elements which have photosensitive parts on an open end face of the optical fibers at the first surface of the substrate is disposed integrally with the substrate, and an end face of the optical fibers at the second surface of the substrate serves as an information reading surface.