The present invention provides a superelastic alloy containing Au in an amount of 8.0% by mass or more and 20.0% by mass or less and at least one of Cr and Mo as essential additive elements, Ta as an optional additive element, and Ti and inevitable impurities as a balance, wherein the Cr equivalent calculated on the basis of the following formula for the relationship of the Cr content, the Mo content and the Ta content is within the range of more than 0.5 and less than 8.0. The alloy is a Ni-free superelastic alloy, and has favorable X-ray-imaging property. Accordingly, the alloy can be suitably used in medical fields. Cr equivalent = Cr content % by mass + Mo content % by mass / 1.7 + Ta content % by mass / 15