a fluorescence detecting apparatus includes : a light source for illuminating the surface of detection of a sample with excitation light ; a ccd area image sensor for detecting fluorescence emitted from the sample ; and a micromirror array device for irradiating excitation light in a 2 - dimensional illumination pattern generated by an information processor based on the detected result from the ccd area image sensor . in this configuration , irradiation of weak excitation light on areas that contain large amounts of fluorescent dyes hence would emit strong fluorescence makes it possible to excite reduced amounts of fluorescence and thereby inhibit adverse effects such as blurring or spreading of light of fluorescent wavelengths around the areas as well as to prevent the high - sensitivity fluorescence detecting device from being saturated by excessive amounts of light . on the other hand , irradiation of strong excitation light on areas that contain lower amounts of fluorescent dyes hence would emit weak fluorescence makes it possible to obtain high enough amounts of fluorescence that can be detected by the fluorescence detecting device .