An endoscope device includes a light source unit that creates multiple excitation lights having different peak wavelengths, an illumination unit, and an imaging unit that includes an objective optical system and an image pickup device. The imaging unit is capable of acquiring images of fluorescent lights having different peak wavelengths that are emitted by multiple fluorescent substances contained in a living organism. The illumination unit transmits the excitation lights to a tip of the endoscope device, and the multiple excitation lights are then directed so as to illuminate a living organism that contains multiple fluorescent substances. A variable transmittance optical element or an array of different type of filters may be placed before the image pickup device to separately detect the multiple fluorescent substances. Specified conditions and transmittances for the variable transmittance optical element and filters are disclosed to insure that the multiple fluorescent substances may be separately detected.