An endoscopy system includes: a motor-driven operating device that an operation section of an accessory is attachable to, the operating device operating the operation section in a motor-driven manner, the accessory having an accessory insertion section to be introduced into a body cavity through an insertion section of an endoscope; a motor-driven forward/backward moving device, arranged in an operation section of the endoscope, for moving the accessory insertion section forward or backward in a motor-driven manner; a control device electrically connected to the motor-driven forward/backward moving device and the motor-driven operating device, the control device including a control unit for outputting control signals to the forward/backward moving device and the operating device and a memory unit for storing one or more treatment operation programs corresponding to accessories to be mounted on the motor-driven forward/backward moving device; and an operation instructing device electrically connected to the control device, the operation instructing device including a first operation instructing unit for outputting a first instruction signal corresponding to the operation of a manual operation unit and a second operation instructing unit for outputting a second instruction signal.