A fluorescence analyzing method includes the steps of irradiating a board, to which oligonucleotide is fixed, with light for fluorescence measurement; focusing produced fluorescence to form an image; and detecting the fluorescence with a two-dimensional sensor. Here, the board is provided with plural regions to which the oligonucleotide is fixed, and the plural regions are spaced apart from one another on the board substantially equidistantly in the vertical and horizontal directions. A fluorescent image is detected in a condition where the following equation is satisfied: dd=ds×M/n where ds denotes the interval between the regions, M denotes the imaging magnification of an optical focusing/imaging system, dd denotes the pixel pitch of the two-dimensional sensor, and n denotes an integer (n=1, 2, 3, 4, 5).