To provide a medical guide wire which is not provided with a projection part in the longitudinal direction, is easy to work, and is excellent in the joining reliability of a joint part for joining a distal end part and a proximal end part.

The medical guide wire is provided with a distal end side member 2 formed of an Ni-Ti based alloy and a proximal end side member 3 formed of SUS304. The joining end part of the distal end side member 2 and the proximal end side member 3 is inserted into an alumina pipe-like joining member 4 having an inner diameter slightly larger than the outer diameter of the joining end part, the joining end face 2a of the distal end side member 2 and the joining end face 3a of the proximal end side member 3 are joined by welding, and then the alumina pipe-like joining member 4 is divided/cut and removed.