Fine metal particles (33) are fixed sparsely to the surface of a transparent substrate (32) and a receptor (35) adsorbing a singular ligand is fixed onto the transparent substrate (32) or the fine metal particles (33). A prism (36) is provided in close contact with the lower surface of the transparent substrate (32), and an exciting light is made to impinge on the transparent substrate (32) through the prism (36). The incident light is totally reflected from the surface of the transparent substrate (32), and local plasmon resonance takes place between the evanescent light generated at the surface and the fine metal particles (33). When plasmon resonance takes place between the evanescent light and the fine metal particles, a strong electric field is confined in the vicinity of the fine metal particles. When the surface provided with the fine metal particles (33) and the receptor (35) is brought into contact with an analysis sample liquid containing a ligand modified with a light-emitting molecule, only the light-emitting molecule with which a singular ligand adsorbed to the receptor is modified emits light.