PROBLEM TO BE SOLVED: To provide an endoscope which is easy to manufacture, can reduce costs, is easy to handle, and can efficiently transmit to a detection part signal light from an object to be observed.SOLUTION: An endoscope 11 includes: an external cylinder 27 of an insertion end part 12； an internal cylinder 21 arranged in a concentric shape to the external cylinder 27； an illumination part 13 emitting illumination light； an optical waveguide 32 transmitting signal light from an object to be observed； and a light detection part 14 detecting signal light transmitted via the optical waveguide 32. The illumination part 13 is arranged in the internal cylinder 21. In the optical waveguide 32, metallic films (27a, 21a) are formed on an inner peripheral surface of the external cylinder 27 and on an outer peripheral surface of the internal cylinder 21 and between an inner peripheral surface of the external cylinder 27 and an outer peripheral surface of the internal cylinder 21. The light detection part 14 is arranged at a position retracted from the optical waveguide 32 and between the inner peripheral surface of the external cylinder 27 and the outer peripheral surface of the internal cylinder 21.SELECTED DRAWING: Figure 2【課題】容易に製造できてコストダウンが図れ、取り扱いも容易にできて、被観察物からの信号光を検出部に効率よく伝送できる内視鏡を提供する。【解決手段】内視鏡１１は、挿入先端部１２の外筒２７と、外筒２７と同心状に配置された内筒２１と、照明光を射出する照明部１３と、被観察物からの信号光を伝送する光導波路３２と、光導波路３２を経て伝送された信号光を検出する光検出部１４とを備える。照明部１３は内筒２１内に配置される。光導波路３２は、外筒２７の内周面及び内筒２１の外周面に金属皮膜（２７ａ、２１ａ）が形成され、外筒２７の内周面と内筒２１の外周面との間に形成される。光検出部１４は、光導波路３２より後退した位置で外筒２７の内周面と内筒２１の外周面との間に配置される。【選択図】図２
