Problem to be solved: to provide a guide wire having a high penetration force while suppressing damage inside the human body such as blood vessels.The guide wire is provided with a core shaft, a tip tip, and a distal end portion of the core shaft which are spaced apart from each other in the axial direction of the guide wire, and can be extended in the axial direction to extend the distance between the tip end and the tip tip of the core shaft by changing or contracting in the axial direction In this case, there is provided a stretchable portion having a diameter reduced from the proximal end toward the tip side.Diagram【課題】血管等の人体内部の損傷を抑制しつつ、穿通力の高いガイドワイヤを提供する。【解決手段】ガイドワイヤは、コアシャフトと、先端チップと、コアシャフトの先端部からガイドワイヤの軸線方向に離間した位置で先端チップを保持し、軸線方向に伸縮することでコアシャフトの先端部と先端チップとの間の距離を変更可能とする伸縮部であって、基端側から先端側に向かって縮径している伸縮部とを備える。【選択図】図２
