A light guide unit (40A, 40B, 40C, 40D, 40E, or 40F) of a fluorescence sensor (10) is disclosed, which includes at least an optical-waveguide film (42a, 42b, 42c, 42d, 92, 102, or 103) in which one or more optical waveguides (54) are formed. Each of these films includes a plurality of optical channels (66) that output excitation light (E) or input fluorescence (F). All the optical channels (66) are covered with a fluorescence unit (60).