This report describes a fracture surgery support system by using an eddy current. In fracture surgery, screw holes on an intramedullary nail are in invisible situation. Although conventional X-ray methods can visualize screw holes in bone, they pose a danger due to X-ray exposure. Therefore, a system to find screw holes without X-ray exposure is required. We solved this problem using a concept of soft computing and searching signals obtained by the eddy current. The screw hole position is lactated by using knowledge on the shape of an intramedullary nail, which means the size of the screw holes and the position of the not flat, after extracting information of the intramedullary nail from the searching signals. By using this knowledge, we can select only needful information. As a result, the screw hole positions could be identified with the smallest error of 0.99 mm when the distance between the probe and the intramedullary nail was 8. 00 mm The screw was successfully inserted to the screw holes in this accuracy.