A tissue fastening apparatus includes a tissue fastening tool, with fastens a first biological tissue and a second biological tissue so as to bring the tissues into close contact and an applicator for indwelling the tissue fastening tool. The tissue fastening tool is made of an elastic wire rod and is wound in a coil shape. The applicator includes a needle tube accommodated in an inner cavity with the tissue fastening tool stretched, a stylet inserted into the inner cavity of the needle tube nearer to the proximal side than the tissue fastening tool, and a rotating mechanism that rotates the stylet around an axis when the stylet is moved toward a distal end of the needle tube. The tissue fastening tool and the stylet are disengageably engaged with each other and integrally and rotatably connected with each other. The rotating mechanism rotates the stylet in a direction opposite to the winding direction of the tissue fastening tool as seen from the proximal side.