PROBLEM TO BE SOLVED: To provide alloy which can be applied to a medical field from the point of view of constituent elements and can exhibit superelastic phenomenon at an ordinary temperature range to conventional Au-Ti-based alloy.SOLUTION: The invention relates to quaternary or quinary Au-based superelastic alloy obtained by adding Mo and/or Nb to Au-Ti-Co alloy. The quaternary or quinary Au-based superelastic alloy comprises, by molar concentration, Au of 27% to 45%, Ti of 46% to 54%, Co of over 10% and less than 17%, Mo of 0.5% or more and less than 3%, and/or Nb of 1% or more and less than 3%, where the total concentration of Au and Co is 44% to 52% and total of Co concentration, Mo concentration and Nb concentration is 18% or less. Mo and Nb can be both added, total of Mo concentration and Nb concentration is 1% or more and less than 3% in that case.
