Abstract: An aluminum-based alloy has high stiffness without containing hard particles such as ceramics, can be produced easily, and is easily processed by machine processing, the alloy contains aluminum as a main element and is shown by the following general formula (1), in which X and Y are respectively selected from Cu, Zn, Ag, and Li, and a and b are values in mass % in which a solid solution is possible by solution heat treatment in this range Al-aX-bY (1).