Disclosed herein is an apparatus for and method of measuring bio-chips, which can implement an illumination method of a novel type that illuminates a bio sample (which may be also referred to as a “bio specimen”) through a side face of a substrate using a diffusion plate to form an evanescent field by the illumination light over the entire surface of a substrate so as to uniformly secure brightness of the illuminated light over a wide area of a substrate, thereby more efficiently measuring fluorescence information of a bio-chip over a wide field of view.