This suture thread pushing apparatus moves a connection portion formed by one end portion and the other end portion of a suture thread used for suturing tissue within a body, which are guided to an outside of the body via a natural orifice, to a sutured portion of the tissue, and includes a flexible outer cylinder, and a flexible shaft member inserted into the outer cylinder so as to advance and retreat, wherein a pair of side holes facing each other is formed in a distal side of the outer cylinder such that the suture thread passes through the side holes, an engaging portion extending in an axial direction of the outer cylinder is formed in an inner surface on the distal side, and an engaged portion engaging with the engaging portion and sliding along the engaging portion is formed on an outer surface of the shaft member.
