To provide a medical guide wire having high bonding strength of a coil spring to a core wire, furthermore, capable of shortening the shaping length when compared to a conventional wire.

A medical guide wire includes a core wire (10) having a distal end-side small diameter portion (11) and a proximal end-side large diameter portion (14) having an outside diameter larger than the outside diameter of the distal end-side small diameter portion (11), and a coil spring (20) which is attached to the outer circumference at the distal end-side small diameter portion (11) of the core wire (10) along the axial direction and is bonded to the core wire (10) at least the front end and rear end thereof, wherein the outside diameter at the proximal end-side large diameter portion (14) of the core wire (10) and the outside diameter of coil of the coil spring (20) are 0.012 inch or less, the front end of the coil spring (20) is bonded to the core wire (10) by an Au-Ge based solder, and the length of the rigid portion at the front end composed of the Au-Ge based solder is 0.1-0.5 mm.