An endoscope system comprises an endoscope (10), manipulating unit (45), and controlling unit (20). The endoscope is equipped with an elongated and flexible insertion tube (11) being inserted into an object being examined and formed to be used in combination with a therapeutic instrument (50). The insertion tube has a distal section accommodating therein at least an optical system for imaging and presenting a longitudinal direction. The manipulating unit (45) is manually manipulated for commanding operations of at least the therapeutic instrument and formed to be loaded to the insertion tube (11) and slidable along the insertion tube in the longitudinal direction thereof. The controlling unit controls at least the therapeutic instrument based on a command from the manipulating unit.