A living body tissue closing device includes an elongated body element, a clip (living body tissue closure) for closing a wound hole which penetrates a living body tissue membrane, and a thread. The body element includes a sheath, and elongated feeding and deformation arrangement. The elongated feeding and deformation arrangement includes a covered tube, a pusher tube, a thread anchoring cap, a guide wire, and a stopper. The clip includes a seal portion for covering the wound hole and a peripheral portion of the wound hole from one side of the living body tissue membrane, a deformation portion deformable between a first form in which the deformation portion can pass through the wound hole and a second form in which the deformation portion cooperates with the seal portion to sandwich the living body tissue membrane therebetween from the other side, and a fastener portion for retaining the deformation portion in the second form.
