A medical screw which can be withdrawn easily from a fracture site in which the medical screw is screwed in is provided. A reverse external thread portion 11h formed in a reverse direction to a direction of a thread of a screw thread portion 11b of a distal end portion 11a is provided on an outer periphery of a head portion 11e of a medical screw 11, and a reverse internal thread portion 14a provided at a front end portion of a rod-shaped member of a withdrawal operating jig 14 is engaged with the reverse external thread portion 11h by rotating in a reverse direction to a direction of a thread of the screw thread portion 11b, whereby the screw 11 and the withdrawal operating jig 14 are unified. Furthermore, the withdrawal operating jig 14 is rotated in a reverse direction to the direction of screwing in of the screw 11, so that the screw 11 is pulled out of the body by being loosened and withdrawn from a fracture site D.
