Abstract: The present invention is an intramedullary nail (100) to be used by being intramedullarily inserted into a bone, having a nail body (110) comprising an axial hole (113) extending from an opening formed at a proximal end portion toward a distal end portion along an axis line and a transverse hole (114) intersecting with the axis line, and having: an engaging member (221) comprising an engaging portion (221b) at distal end thereof engageable with a bone fastener inserted through the transverse hole and arranged so as to be shiftable in the axial hole in a manner where the distal end portion is engageable and disengageable with the bone fastener (10); an adjusting member (222) controlling the position of the engaging member; and an elastic member (125) for charging, against the nail body, the engaging member in a direction opposite the controlling direction by the adjusting member.