An endoscope apparatus can perform observation using fluorescence generated in response to irradiation of excitation light to a fluorescent dye administered into a subject and reference light that is light in a wavelength band different from fluorescence. The objective optical system into which the insertion part that can be inserted into the subject, the fluorescence, the reflected light of the reference light, and the reflected light of the excitation light are incident, and the light emitted through the objective optical system are mutually connected. A spectral element that separates light into a plurality of different wavelength bands, an imaging unit that includes an imaging element for imaging fluorescence separated by the spectral element, and light that enters from the objective optical system reaches the imaging element. And a filter unit that blocks the reflected light of the excitation light and blocks the reflected light of the reference light before the light emitted through the spectroscopic element reaches the imaging device.内視鏡装置は、被検体内に投与された蛍光色素に対する励起光の照射に応じて発生する蛍光と、蛍光とは異なる波長帯域の光である参照光と、を用いた観察を行うことができ、被検体内に挿入可能な挿入部と、蛍光と、参照光の反射光と、励起光の反射光と、が入射される対物光学系と、対物光学系を経て出射される光を相互に異なる複数の波長帯域の光に分離する分光素子と、分光素子により分離された蛍光を撮像するための撮像素子を具備する撮像部と、対物光学系から入射した光が撮像素子に至るまでに励起光の反射光を遮断し、分光素子を経て出射された光が撮像素子に至るまでに参照光の反射光を遮断するフィルタ部と、を有する。
