The applicator related to the present invention is provided with a flexible sheath longer than the overall length of an instrument channel of a flexible endoscope an operation part used outside the instrument channel a deployed section that can be made to protrude from the front end of the sheath by operating the operation part and to pierce a tissue a tissue fastening tool made of a superelastic wire formed in coil shape and housed inside the deployed section in a substantially extended condition and a pusher that pushes out the tissue fastening tool from the deployed section when the operation part is operated.
