The present invention is an alloy for medical use including an Au-Pt alloy, containing 34 to 36 mass% of Pt with the balance being Au, and having an ±-phase single structure in which a ratio of a peak intensity (X) of a Pt (111) plane to a peak intensity (Y) of an Au (111) plane (X/Y) is 0.01 or less in an X-ray diffraction analysis. The alloy can be produced in such a manner that after the Au-Pt alloy ingot is molten and cast, cold working and a heat treatment for homogenization are performed at least two times on the molten and cast alloy. The alloy of the present invention is an artifact-free material that exhibits excellent compatibility with a magnetic field environment such as an MRI and has magnetic susceptibility of ± 4 ppm with respect to that of water.
