The present invention, in an endoscope having a bi-directional bending mechanism and an insertion portion rotation mechanism, achieves downsizing and improves assembly while providing a rotation amount detection sensor unit of the insertion portion in the internal space of the operation portion. Therefore, the endoscope of the present invention includes an operation unit 12 and an insertion unit that is connected to the distal end side of the operation unit so as to be rotatable around a longitudinal axis. 11, a conversion unit 30 provided at the proximal end of the insertion unit for converting the rotation of the insertion unit into a displacement in the longitudinal axis direction, a transmission unit 42 for transmitting the displacement generated by the conversion unit in the longitudinal axis direction, and an operation And a detection sensor 41 for detecting the displacement transmitted by the transmission unit.本発明は、二方向湾曲機構と挿入部回動機構とを備えた内視鏡において、挿入部の回動量検出センサユニットを操作部の内部空間に設けつつ小型化を実現し組立性の向上にも寄与し得る内視鏡を提供することを目的とし、そのために、本発明の内視鏡は、操作部１２と、操作部の先端側に長手軸周りに回動可能に連結された挿入部１１と、挿入部の基端部に設けられ挿入部の回動を長手軸方向の変位に変換する変換部３０と、変換部により生じた変位を長手軸方向に伝達する伝達部４２と、操作部に配設され伝達部により伝達された変位を検出する検出センサ４１とを具備する。
