A lesion extracting device includes a light source for emitting an excitation light toward a subject body, a control unit for changing an amount of the excitation light, a light irradiating and receiving portion for irradiating the excitation light to the subject body and receiving fluorescence generated from the subject body, a distance holding member for holding a distance between the subject body and the light irradiating and receiving portion at a predetermined value, a measuring unit for measuring the intensity of the fluorescence received by the light irradiating and receiving portion, and an extracting unit for extracting a lesion part of the subject body based on relationships between measured values of changes in the fluorescence intensity with respect to changes in the amount of the excitation light and information regarding the changes in the amount of the excitation light, the information being obtained from the control unit.
