A catheter and guide wire in which at least a distal end portion of a catheter body or guide wire is formed of a shape memory-specialized metal having shape memory property, but free from superelasticity or pseudoelasticity at least at the body temperature, have high safety and improved operability as compared with prior art ones and are advantageously used in a wide range of examination and treatment, especially in angiography, angioplasty, embolization, foreign matter removal and recovery, calculus capture and so on.