A ligating-apparatus includes a clip, an operating wire, an inner sheath member and an outer sheath member. The clip ligates a body tissue with arms. The operating wire pulls the clip. The inner sheath member encloses the operating wire to support a clip holding member. The outer sheath member advances and retreats while covering the inner sheath member. The outer sheath member changes the degree of opening of the arms by causing each arm to abut on an inner peripheral surface thereof. A pair of arms includes first arm portion and a second arm portion connected continuously to the first arm portion via a bending portion. When the bending portion abuts against an inner peripheral surface end portion of the outer sheath member, the second arm portion is arranged at an inner side in a direction of a radius from an inner peripheral surface of the outer sheath member.
