The endoscope 1 includes an insertion portion 2, a distal end surface 14 a capable of receiving light from the object to be observed, a detection fiber 14 that transmits light received by the distal end surface 14 a, an opening that opens in the vicinity of the distal end surface 14 a A treatment instrument insertion channel 16 inserted into the insertion portion 2, an endoscope main body portion 3 connected to the insertion portion 2, and an endoscope main body portion 3 provided in the endoscope main body portion 3 and having a treatment instrument insertion channel 16 An external detection fiber 10 which is provided in the endoscope main body 3 and is capable of guiding light between the outside and the inside of the endoscope main body 3, an endoscope And a confluence portion 15 that is provided inside the mirror main body portion 3 and joins the light transmitted by the detection fiber 14 and the light guided by the external detection fiber 10.内視鏡1は、挿入部2と、被観察体からの光を受光可能な先端面14aと、先端面14aで受光した光を伝達する検出ファイバ14と、先端面14aの近傍に開口する開口部17と、挿入部2内に挿通された処置具挿通チャンネル16と、挿入部2に連設された内視鏡本体部3と、内視鏡本体部3に設けられ、処置具挿通チャンネル16に連通する開口を有する処置具挿通口7と、内視鏡本体部3に設けられ、内視鏡本体部3の外側と内側との間で導光可能な外付け検出ファイバ10と、内視鏡本体部3の内側に設けられるとともに、検出ファイバ14により伝達された光と、外付け検出ファイバ10により導光された光とを合流させる合流部15と、を有する。
