A fluorescence sensor 10 includes a detection substrate section 20, on a first principal plane 21 of which a concave portion 23 having a bottom surface 22 parallel to the first principal plane 21 is present and, on a side surface 24 of the concave portion 23 of which a PD element 13 configured to receive fluorescent light F and output a detection signal is formed, an LED element 12 disposed on the bottom surface 22 of the concave portion 23 of the detection substrate section 20 and configured to generate excitation light E, and an indicator layer 16 disposed on an inside of the concave portion 23 on the LED element 12 and configured to generate the fluorescent light F corresponding to the excitation light E and an analyte amount.
