A tissue closing device includes an elongate arrangement device of which a distal end portion can penetrate an opening on a wall of living body cavity and which has a hand-operated portion on the proximal side, and a closure detachably retained at the distal end portion of the arrangement device and operative to close the opening. According to one embodiment, the arrangement device can include a thread for detachably retaining the closure and for pulling the closure in the proximal direction, a cover tube, and a fixed tube. The hand-operated portion has a canceling mechanism for canceling the retained state of the closure. A series of operations from deformation of the closure resulting from pulling the closure by the thread to canceling the retained state of the closure by the canceling mechanism after completion of the deformation are performed continuously by operating the hand-operated portion.