It comprises a fixing device (1) for fixing a bone fragment due to a fracture, and the sleeve (2) has an opening rear end (4) and a front end (5), and at least one opening ( 8), and the pin (9) is configured to be displaced in a forward direction with respect to the sleeve (2), and at least one front end (10) of the pin is opened to the outside of the sleeve via the opening (8) opened in the sleeve. Drive to insert into the bone plate of the bone fragment, the front end (10) of the pin (9) is external to the sleeve (2) via an opening (8) that opens into the sleeve (2) during operation. And the pin (9) is configured to be displaced in the opposite direction with respect to the sleeve (2) to retract the front end (10) of the pin. Bone fragment configured to be led out of bone material and returned into the sleeve In the fixing device, the pin (9) includes a fixing member (9a), a front end portion (10), and a driving retreating member (9b) rotatably connected to the fixing member. 9b) the pin fixing member (9a) displaces the pin in the forward direction relative to the sleeve (2) when the drive retreating member rotates in the first direction, and drives the front end (10) of the pin to the outside of the sleeve. Then, the front end of the pin is displaced into the one bone by displacing the pin in the opposite direction with respect to the sleeve in the second reversing stage with respect to the fixing member of the advancement / retraction member. It is configured to be retracted or pulled out of the bone member within the piece and then inserted into the sleeve. [Selection] Figure 3骨折による骨片を固定させる固定装置（１）からなり、スリーブ（２）は開口後端部（４）と前端部（５）とを有し、さらにスリーブの長手側面に少なくとも一つの開口部（８）を設け、ピン（９）はスリーブ（２）に対する前進方向に変位するよう構成されてピンの少なくとも一つの前端部（１０）をスリーブに開口した開口部（８）を介してスリーブ外に駆動して骨片の一つの骨板中に挿入させ、ピン（９）の前端部（１０）は操作中にスリーブ（２）に開口した開口部（８）を介してスリーブ（２）の外部に突出して前記一つの骨片内の骨材と係合し、さらにピン（９）はスリーブ（２）に対して逆方向に変位するよう構成されてピンの前端部（１０）を後退させて骨片の骨材料の外部に導出させスリーブ内に戻すように構成した骨片固定装置において、ピン（９）は固定部材（９ａ）と前端部（１０）と固定部材に回動自在に接続される駆動後退部材（９ｂ）と
