To allow alleviating of pains inflicted on a subject during the observation while simplifying the structure of an insertion/removal mechanism by arranging an exciter filter to have a wavelength characteristic of transmitting infrared rays.

An observation/photographing system 51 is roughly constituted of a common optical system 52, an observation system 53 and a photographing system 54. A lighting system 50 has a concave mirror 55, a halogen lamp 56, a condenser lens 57, a infrared transmission filter 58, a circular xenon lamp 59, a ring stop 60, a relay lens 61, a black spot plate 62, focusing index mechanism 63 and a relay lens 64. The infrared transmission filter 58 serves to transmit infrared rays with the wavelength thereof exceeding about 830nm and the exciting filter 67 serves to transmit illumination light as photographing light with the wavelength of 450nm to 520nm and illumination light as infrared rays with the wavelength exceeding 820nm.