This treatment system includes: a supporting portion a first grasping member and a second grasping member supported by the supporting portion so as to approach and separate from each other a needle member including a distal end portion which has a sharp distal end and punctures a tissue, and a proximal end portion continuous with the distal end portion a holding portion mounted on the first grasping member and releasably holding the proximal end portion of the needle member and a locking portion mounted on the second grasping member and locking the distal end portion of the needle member such that the proximal end portion of the needle member is removed from the holding portion when the first grasping member and the second grasping member are separated from each other from a position at which the first grasping member and the second grasping member approach each other.
