To provide a method for selectively recovering rare-earth elements alone from a mixed solution of various elements including the rare-earth elements.

Particles of polyesters having, as monomer units, 3-hydroxy-5-phenoxyvaleric acid and 3-hydroxyalkanoic acid and 3-hydroxyalkenoic acid (saturated or unsaturated fatty acid of 4 to 12 carbon atoms, e.g., 3-hydroxybutyric acid, 3-hydroxyvaleric acid, etc.) are exposed to the mixed solution of various elements including the rare-earth elements. By this method, the rare-earth elements alone can be selectively separated and recovered.