A suture-needle holder, provided with: a sheath part; a pair of clamping members provided to the distal end part of the sheath part; an operation wire connected to the pair of clamping members, the operation wire being movable relative to the sheath part; an operation part body formed as a shaft extending along a longitudinal axis, the operation part body being connected so as to be movable relative to the sheath part in a direction aligned with the longitudinal axial and about the longitudinal axis; and a traction member fixed to the proximal end part of the operation wire and movably attached to the operation part body, the traction member moving the operation wire relative to the operation part body in the direction aligned with the longitudinal axial. A first groove part and a second groove part are formed in the outer peripheral surface of the operation part body, the first groove part extending along the longitudinal axis, and the second groove part having a distal end part continuous with the proximal end part of the first groove part, and extending progressively farther around the longitudinal axis the closer the second groove is to the proximal end. A protruding part capable of moving within the first groove part and the second groove part is provided to the sheath part.