The invention aims to provide an optical information reader which can identify precisely, reliably, and with high sensitivity, even when the quantity or the wavelength of light from a measuring object from which optical information is to be read, extends over a wide range. The optical information reader comprises: a substrate on which one or more biological materials labeled by a combination of presence or extent of a plurality of kinds of optical labeling elements are immobilized at one or more different immobilized positions; one or more light-receiving ends capable of receiving light from the substrate; an optical information measuring unit which obtains optical information on a specific measuring object on the substrate based on an electric signal obtained by converting the light received by the light-receiving end by photoelectric elements having different characteristics determined depending on the measuring object; and a scanning unit which scans the substrate by moving the substrate and the light-receiving end relative to each other, and the optical information measuring unit has an optical waveguide.