A clipping instrument for an endoscope is provided. The clipping instrument includes a flexible sheath, an operation wire, at least one detachable clip assembly, including a pair of openable and closable clipping arms and a fastening ring, the clipping arms being configured to be projected forward to open and to be closed according to forwarding and retracting movements of the fastening ring through the operation wire, a withdrawal stopper and an advancement stopper, which are provided in the vicinity of the distal end portion of the flexible sheath. The withdrawal stopper restricts the fastening ring from being retracted rearward into the withdrawal stopper once the fastening ring is forwarded to penetrate through the withdrawal stopper. The advancement stopper restricts the fastening ring from being forwarded further to penetrate out of the advancement stopper once the fastening ring is forwarded to penetrate through the withdrawal stopper.
