A rotary self-advancing endoscope system which produces propulsion by rotating, with a motor, a rotating cylindrical body provided on an outer periphery side of an insertion portion main body and causes the insertion portion main body to move forward into an examinee's body, wherein the system is configured to periodically repeating a combination of a state in which the rotating cylindrical body forward-rotates at a predetermined RPM and a state in which the rotating cylindrical body is stopped from rotating and releases accumulated elastic energy and, when a drive current to the motor has reached a predetermined threshold value, reverse-rotate the motor.