Provided is an imaging device that makes it possible to suitably carry out observation of a fluorescence image without overlooking emitted fluorescence. An endoscope system (1) is provided with: a special light source (42) that emits excitation light toward a subject, said excitation light being used to excite a fluorescence material that is introduced into the subject a white light source (41) that emits normal light toward a subject, said normal light comprising a visible bandwidth that differs from the excitation light an imaging element (244) that comprises an imaging surface that captures an optical image of the subject that is illuminated by the excitation light or the normal light and generates an image signal of the optical image a brightness detection unit (303) that generates a luminance signal that indicates brightness on the basis of the image signal that is generated by the imaging element (244) under illumination by the normal light and an amplification unit (309a) that sets the amplification rate of the image signal that is generated by the imaging element (244) under illumination by the excitation light using an amplification rate that corresponds to the luminance signal that is generated by the brightness detection unit (303).Linvention concerne un dispositif dimagerie qui permet de réaliser de manière appropriée lobservation dune image de fluorescence sans négliger la fluorescence émise. Selon linvention, un système dendoscope (1) est équipé de : une source lumineuse particulière (42) qui émet de la lumière dexcitation vers un sujet, ladite lumière dexcitation étant utilisée pour exciter un matériau fluorescent qui est introduit dans le sujet une source lumineuse blanche (41) qui émet de la lumière normale vers le sujet, ladite lumière normale comprenant une largeur de bande visible qui diffère de la lumière dexcitation un élément dimagerie (244) qui comprend une surface dimagerie qui capture une image optique du sujet qui est éclairé par la lumi
