The present invention with the diameter of the core wire to the coil body, there is provided a rotation transmission performance to the distal end side, a medical guidewire with improved drilling performance of the lesion. A core wire distal end portion 2B in the coil body 3 has an articulated truncated cones that connected to the longitudinal direction of the at least two truncated cones, the second moment from the rear end side to the distal side By but satisfying a certain relational expression, when you rotate the core wire 2 of the proximal side, to reduce the rotation angle of the proximal side, and to improve the drilling performance of the occlusion lesion by increasing the torsional moment in the tip side I can.BACKGROUND.【課題】コイル体内へ芯線の細径化に伴い、先端側への回転伝達性能と、病変部の穿孔性能を向上させた医療用ガイドワイヤを提供する。【解決手段】コイル体3内の芯線先端部2Bは、少なくとも2個以上の截頭円錐体を長手方向に連接した連接截頭円錐体を有し、後端側から先端側へ断面二次モーメントが一定の関係式を満たすことにより、手元側の芯線2を回転操作したとき、手元側の回転角度を減少させ、先端側へのねじりモーメントを増大させて閉塞病変部の穿孔性能を向上させることができる。【選択図】図1
