To provide a medical guide wire wherein a fluorine-based resin coating layer for exhibiting lubricity is firmly bonded onto the surface of a metal wire, and which prevents the resin coating layer from peeling from the surface of the metal wire during operation.

In a medical guide wire, a fluorine-based resin coating layer 50 is formed on a colored oxide film 20C formed on the surface of a stainless wire 20B by heat-treating the stainless wire at 300-450°C. Preferably, the fluorine-based resin coating layer 50 is made of PTFE.