An external mechanism for endoscope includes a wheel configured to be engaged with a second bending operation up and down knob of a second bending operation apparatus provided in an operation portion of an endoscope, a motor configured to generate driving force for rotating the wheel, an operation switch configured to output a driving control signal for the motor, a container case that contains the wheel and the motor, a case attachment and detachment fixation member with which the container case can be attached to and detached from the operation portion, and a switch case attached to the container case and configured to be able to turn between a first position that covers a part of the operation portion and a second position away from the first position.