The present invention relates to a medical Au—Pt—Pd alloy including Au, Pt, Pd, and inevitable impurities. The alloy has an alloy composition inside a polygon (A1-A2-A3-A4-A5-A6) surrounded by straight lines connected at point A1 (Au: 37.9 atom %, Pt: 0.1 atom %, and Pd: 62 atom %), point A2 (Au: 79.9 atom %, Pt: 0.1 atom %, and Pd: 20 atom %), point A3 (Au: 79.9 atom %, Pt: 20 atom %, and Pd: 0.1 atom %), point A4 (Au: 69.9 atom %, Pt: 30 atom %, and Pd: 0.1 atom %), point A5 (Au: 49 atom %, Pt: 30 atom %, and Pd: 21 atom %), and point A6 (Au: 39 atom %, Pt: 40 atom %, and Pd: 21 atom %) in a Au—Pt—Pd ternary state diagram. The metal structure of the alloy is optimized, and the metal structure is close to a single-phase structure, and has little precipitation of a Au-rich phase and a Pt-rich phase different in composition from a mother phase.