Supernatant of the urinary sample (SP1) was mixed with an acid or alkali and heated (SP2) and the sample for fluorescence assay was prepared after adjusting its acidity to alkaline (SP3). Next, using fluorometry, three-dimensional fluorescence spectrum consisted of an excitation light wavelength, fluorescence wavelength and fluorescence intensity (SP4). Then, a relative maximum peak is detected as a specific point in the three-dimensional fluorescence spectrum to specify a specific point attribute (peak number, peak position and fluorescence intensity) and then the urinary sample is sorted based on the attribute (SP5). Finally, the presence or absence of a disease such as a malignant tumor is determined based on the sorting results of the urinary sample (P6).