To individually acquire autofluorescence information based on autofluorescence and chemical agent fluorescence information based on chemical agent fluorescence from a part to be tested administered with a fluorescent chemical agent.

This fluorescence detecting system emits an excitation light L1 with a wavelength of 750 nm to a part 1 to be tested of a subject previously administered with the fluorescent chemical agent, and captures the image of the chemical agent fluorescence emitted from the fluorescent chemical agent with a CCD image pickup device 107 to acquire the fluorescence image information. This system also emits an excitation light L2 with a wavelength of 410 nm thereto, and captures the image of the autofluorescence emitted from the part 1 to be tested with a CCD image pickup device 107 to acquire the autofluorescence information. The administered fluorescent chemical agent which is excited by the light with the a wavelength of 750 nm but not excited by the light with the a wavelength of 410 mm so as to prevent the mixing between the wavelength band of the chemical fluorescence and the wavelength band of the autofluorescence. The image based on the autofluorescence information and the image based on the chemical agent fluorescence information are displayed in parallel to each other or superimposedly disposed on a monitor 161.