A
blood test method includes: a preparation step of preparing
whole blood collected from a subject; a pretreatment step for preparing a sample for analysis by pretreating the
whole blood; a separation step in which the sample for analysis is separated by components using a liquid chromatograph; and an analysis step for analyzing the separated component using a
mass spectrometry device, the subject being administered with a first immunosuppressant comprising at least one substance selected from the group consisting of
tacrolimus,
cyclosporin A,
everolimus, and
sirolimus, and with a second immunosuppressant comprising at least one substance selected from the group consisting of
cyclosporin A,
everolimus, and
sirolimus. The second immunosuppressive agent contains at least one substance selected from the group consisting of mycophenolic acids and metabolites thereof, the separated component contains the first immunosuppressive agent and the second immunosuppressive agent, and when the first immunosuppressive agent is analyzed as a target component in the analysis using the
mass spectrometry device, the first immunosuppressive agent is separated from the target component, and when the second immunosuppressive agent is separated from the target component, the second immunosuppressive agent is separated from the target component. When the first immunosuppressive agent is analyzed as a target component, analysis is performed in a positive
ion pattern, and when the second immunosuppressive agent is analyzed as a target component, analysis is performed in a negative
ion pattern.