A fluorescence sensor 10 includes a silicon substrate 11 on which a PD element 12 that converts fluorescence into an electric signal is formed, an LED substrate 15 having a first principal plane 15A on which an LED element 15C that generates excitation light is formed, a reflective film 20 that averages a light amount distribution of the excitation light radiated from a second principal plane 15B of the LED substrate 15, and an indicator layer 17 that receives the excitation light averaged by the reflective film 20 and generates the fluorescence having a light amount corresponding to an analyte amount.
