To improve the recovery ratio (extraction ratio) of a noble metal, particulally the recovery ratio of rhodium by using hydrochloric acid and sulfuric acid as extraction solvents.

An automobile exhaust gas purifying waste catalyst composed of a cordierite made honeycomb carrier is pulverized into ≤100 mesh. The pulverized waste catalyst is charged by 200g into a l000ml glass vessel and next, 400ml hydrochloric acid of 12N and 40ml sulfuric acid of 36N are added. While stirring by a stirring blade 4 with a stirring motor 6, 20ml sodium hypochlorite solution of 20wt.% is added and sealed in the vessel 1 by mounting a cap with a packing 5. The glass vessel 1 is charged into a silicone oil bath 2 and heated from the bottom of the silicone oil bath by an electric heater 3. The content starts to boil at 108°C and is kept at 120°C for 5hr by controlling the electric heater 3. Next, the content in the glass vessel 1 is taken out and separated into an extracted solution and a dissolution residue. The noble metal is recover as a metal from the separated solution.