The purpose of the present invention is to reduce correction errors and obtain quantitative information about a photographic subject. Provided is a fluorescence observation device (100) that sets at least either a first coefficient or a second coefficient such that a threshold setting unit (45) reflects input results input using an input unit (53), and comprises: a light source (10) a fluorescent image generation unit (41) that obtains a fluorescent image (G1) of a photographic subject (F) irradiated with excitation light a white-light image generation unit (42) that obtains a white-light image (G2) of the photographic subject (F) irradiated by illumination light an image correction unit (43) that generates a corrected fluorescent image (G3), using these images (G1, G2) the threshold setting unit (45) that sets a threshold on the basis of the average value of the gradation values for the image (G3) overall and the first coefficient therefor and on the standard deviation for the gradation values for the image (G3) and the second coefficient therefor an extraction unit (47) that determines, as an observation area, an area in the image (G3) having a gradation value exceeding the threshold, and extracts same a monitor (50) that associates this observation area and the image (G2), and displays same and the input unit (53) that causes an observer to input whether or not a determination by the extraction unit (47) is correct.La présente invention vise à réduire des erreurs de correction et obtenir des informations quantitatives à propos dun sujet photographique. Linvention porte également sur un dispositif dobservation de fluorescence (100) qui règle au moins soit un premier coefficient, soit un second coefficient de telle sorte quune unité de réglage de seuil (45) réfléchit une entrée de résultats dentrée à laide dune unité dentrée (53), et qui comprend : une source de lumière (10) une unité de génération dimage fluorescente (41) qui obtient une image fluorescente (G1)
