PROBLEMS A separation unit can confirms a separation state, a detection unit enhances a lighting efficiency and a light reception sensitivity, and a dispensing unit ensures the normal state of a specimen. The method includes a first analyte-specific receptor that contains at least two binding sites for the analyte, and a second analyte-specific receptor that selectively binds to an aggregate arrangement of at least two analyte molecules bound to the first receptor. Thermal oxidation of the base causes a germanium-enriched region to form on a surface of the silicon-germanium portion subjected to the thermal oxidation.