To provide a method of efficiently removing excitation light in a device for measuring fluorescence emitted from samples on a measuring surface of a substrate while illuminating the samples with excitation light. The method is a fluorometry characterized in that an excitation light illumination portion where the samples are illuminated with the excitation light and a light detecting portion where measurements are made of the fluorescence are placed in such a manner as to make it possible to prevent the excitation light from approaching the light detecting portion, and measurements of the fluorescence emitted from the samples on the measuring surface of the substrate are made in such a manner as to relatively move the samples from the excitation light illumination portion to the light detecting portion after illuminating the same with the excitation light.