The present invention has an object to provide a method for efficiently detecting an image with a smaller number of pixels.The invention relates to fluorescence analysis which uses a substrate having a plurality of regions for being capable of immobilizing biologically-related molecules in positions of lattice points of a lattice structure, and which causes the fluorescence from a certain lattice point to be wavelength-dispersed in a direction other than the direction toward the adjacent closest lattice point. According to an embodiment, for example, the number of pixels of a two-dimensional sensor required for fluorescence analysis of the regions with the biologically-related molecules immobilized can be set to several hundred times to fifty times smaller than that in the conventional case without degrading the measurement accuracy. This can achieve the improvement of throughput, reduction in price, and/or improvement of the operability of an analyzing device.