A magnesium alloy is provided that includes: 5.0 mass % or more and 15.0 mass % or less of Al; 2.5 mass % or more and 7.0 mass % or less of Sr; 0.05 mass % or more and less than 3.0 mass % of Ca; and 0.1 mass % or more and 0.6 mass % or less of Mn, with a remainder including Mg and inevitable impurities.