This endoscope operation mechanism is provided with: a first operation member 4 which rotates about an axis Ax； a second operation member 5 which rotates about the axis to restrict the rotation of the first operation member； a movable member 22 which moves between a first position at which the movable member allows the first operation member to rotate and a second position which is spaced axially apart from the first position and at which the movable member restricts the rotation of the first operation member； a support member 24 spaced axially apart from the movable member； a friction member 23 which, when the movable member moves from the first position to the second position, is compressed and deformed between the support member and movable member, and applies a friction force to the rotation of the first operation member in order to restrict the rotation of the first operation member； a cam member 26 which has a cam face 126 in contact with the movable member, and moves the movable member between the first position and second position in response to external input from the second operation member； and a click mechanism 105 for holding the cam member at the first and second positions. The amount of axial movement of the movable member by means of the cam face becomes moderate in the course of the movable member compressing the friction member.Ce mécanisme d'actionnement d'endoscope comprend : un premier élément d'actionnement (4) qui tourne autour d'un axe Ax ； un second élément d'actionnement (5) qui tourne autour de l'axe pour limiter la rotation du premier élément d'actionnement ； un élément mobile (22) qui se déplace entre une première position dans laquelle l'élément mobile permet au premier élément d'actionnement de tourner et une seconde position qui est espacée axialement de la première position et au niveau de laquelle l'élément mobile limite la rotation du premier élément d'actionnement ； un élément de support (24) espacé axialement de l'élément mobile
