The endoscope has a rigid distal end constituent part provided on a distal end side of an insertion part to be inserted into a subject and a pivot shaft rotatably held with respect to the distal end constituent part, What is claimed is: 1. An endoscope comprising: a rotating part that pivots about an axis an exterior body that is detachably mounted on the distal end constituting part and an outer casing provided so as to be recessed from an outer surface of the distal end constituent part so as to face the exterior body, A bearing which displaces the rotating shaft from the distal end constituting portion by detaching the exterior body from the distal end constituent portion, and a bearing which holds one of the rotating portion and the distal end constituting portion And a blocking portion which contacts the other of the turning portion and the tip forming portion when the turning shaft is displaced from the bearing and prevents the turning portion from coming off .内視鏡は、被検体に挿入される挿入部の先端側に設けられる、硬質な先端構成部と、前記先端構成部に対して回転自在に保持される回動軸を有し、前記回動軸を中心に回動する回動部と、前記先端構成部に着脱可能に装着される外装体と、前記外装体に対面して前記先端構成部の外面から窪んで設けられ、前記回動軸を受容して支持するとともに、前記外装体が前記先端構成部から取り外されることにより、前記先端構成部から前記回動軸を変位させる軸受と、前記回動部および前記先端構成部のいずれか一方に設けられ、前記回動軸が前記軸受から変位させられたとき、前記回動部および前記先端構成部のいずれか他方と接触して前記回動部の離脱を阻止する阻止部と、を有する。
