An endoscope operation mechanism 40 includes: a dial 42 configured to operate an endoscope function； a detection sensor 45 that has a sensor rotation shaft 45a to which rotation of a dial rotation shaft 42a of the dial is transmitted and detects the rotation amount, and that outputs an electrical signal in accordance with the detected rotation amount to a control portion that performs driving control of a driving source of the endoscope function； an initial position reversion mechanism 44 that applies a rotational force to the dial rotation shaft 42a in an opposite direction to the direction in which the dial rotation shaft 42a is rotated, to thereby cause the rotational position of the dial 42 to return to an initial position； and a switching mechanism 50 which is switchable between a first state in which a rotational force from the initial position reversion mechanism is applied to the dial rotation shaft 42a, and a second state in which the rotational force is not applied to the dial rotation shaft 42a.
