A sample analyzer for analyzing a measurement specimen containing a plurality of kinds of target substances each labeled with a fluorescent dye, the sample analyzer comprising: a measurement unit comprising: a flow cell allowing the measurement specimen to flow therethrough; a light source (121,... 126) configured to apply light (λ11,... λ16) to the measurement specimen flowing through the flow cell to generate, from the fluorescent dye, a plurality of kinds of fluorescences (λ21,... λ25) having different wavelengths; an imaging unit configured to take an image of the fluorescence (λ21,... λ25) generated from a cell in the measurement specimen flowing through the flow cell, for each color of the fluorescence (λ21,... λ25), and generate a fluorescence image; and a processing unit configured to analyze the target substances based on the fluorescence image and information on colors of fluorescences (λ21,... λ25), which is set to be variable so as to correspond to the plurality of kinds of target substances, wherein the analyzing the target substances comprises: receiving information on colors of fluorescences (λ21,... λ25) corresponding to the respective target substances; obtaining a positive pattern and a negative pattern based on the information on colors of fluorescences (λ21,... λ25), the positive pattern and the negative pattern being bright point patterns; extracting a fluorescence region from the fluorescence image and obtaining a bright point pattern of the cell based on the fluorescence region and the information on colors of fluorescences (λ21,... λ25); and determining whether the cell is positive or negative by comparing the bright point pattern of the cell with the positive pattern and the negative pattern. a measurement unit comprising: a flow cell allowing the measurement specimen to flow therethrough; a light source (121,... 126) configured to apply light (λ11,... λ16) to the measurement specimen flowing through the flow cell to generate, from the fluorescent dye, a plurality of kinds of fluorescences (λ21,... λ25) having different wavelengths; an imaging unit configured to take an image of the fluorescence (λ21,... λ25) generated from a cell in the measurement specimen flowing through the flow cell, for each color of the fluorescence (λ21,... λ25), and generate a fluorescence image; and a flow cell allowing the measurement specimen to flow therethrough; a light source (121,... 126) configured to apply light (λ11,... λ16) to the measurement specimen flowing through the flow cell to generate, from the fluorescent dye, a plurality of kinds of fluorescences (λ21,... λ25) having different wavelengths; an imaging unit configured to take an image of the fluorescence (λ21,... λ25) generated from a cell in the measurement specimen flowing through the flow cell, for each color of the fluorescence (λ21,... λ25), and generate a fluorescence image; and a processing unit configured to analyze the target substances based on the fluorescence image and information on colors of fluorescences (λ21,... λ25), which is set to be variable so as to correspond to the plurality of kinds of target substances, wherein the analyzing the target substances comprises: receiving information on colors of fluorescences (λ21,... λ25) corresponding to the respective target substances; obtaining a positive pattern and a negative pattern based on the information on colors of fluorescences (λ21,... λ25), the positive pattern and the negative pattern being bright point patterns; extracting a fluorescence region from the fluorescence image and obtaining a bright point pattern of the cell based on the fluorescence region and the information on colors of fluorescences (λ21,... λ25); and determining whether the cell is positive or negative by comparing the bright point pattern of the cell with the positive pattern and the negative pattern. receiving information on colors of fluorescences (λ21,... λ25) corresponding to the respective target substances; obtaining a positive pattern and a negative pattern based on the information on colors of fluorescences (λ21,... λ25), the positive pattern and the negative pattern being bright point patterns; extracting a fluorescence region from the fluorescence image and obtaining a bright point pattern of the cell based on the fluorescence region and the information on colors of fluorescences (λ21,... λ25); and determining whether the cell is positive or negative by comparing the bright point pattern of the cell with the positive pattern and the negative pattern.