In a first measurement stage, reaction solutions of samples are optically measured by a biochemical analyzer, and the measurement result of the analysis item which is an index of the disease status regarding the samples is compared with the check index. This check index is stored in memory beforehand. When the measurement result corresponds to the check index, the sample processing goes to a second measurement stage for measuring a specific item. In the second measurement stage, the sample is measured by an immuno-assay apparatus or a nucleic acid analyzer, and the measurement result is outputted.