The endoscope is provided along the longitudinal axis direction of the insertion portion to be inserted into the subject and guides illumination light for illuminating the subject in the subject from the proximal end portion of the insertion portion to the distal end portion A light entrance surface provided at the distal end portion of the insertion portion and adapted to receive the illumination light transmitted by the light guide portion by coming into contact with the end portion of the light guide portion An illumination section having at least a light exit surface that emits light to at least the side of the insertion section and an illumination section that is provided on the proximal side of the illumination section and that covers the light guide section along the longitudinal axis, And a translucent window formed in a portion where the light incident surface and the end portion of the light guide portion in the housing can be visually recognized simultaneously from the outside.内視鏡は、被検体内に挿入される挿入部の長手軸方向に沿って設けられ、被検体内の被写体を照明するための照明光を挿入部の基端部から先端部へ伝送する導光部と、挿入部の先端部に設けられ、導光部の端部と接触することで導光部により伝送された照明光を入射させる光入射面と、光入射面から入射した照明光を少なくとも挿入部の側方に出射する光出射面とを有する照明部と、照明部よりも基端側に設けられ、前記導光部を前記長手軸方向に沿って覆うように形成された、遮光性を有するハウジングと、ハウジングにおける光入射面と導光部の端部とを外部から同時に視認可能な部分に形成された、透光性を有する窓と、を有する。
