a method of recovering a decomposition product from a polyurethane , the method comprising the steps of thermally decomposing a polyurethane into a liquid containing a polyol and a urea compound which is soluble in the polyol , and solids containing a urea compound which is insoluble in the liquid in the presence of a polyamine compound at a temperature of 120 to 250 ° c . ; removing the solids ; hydrolyzing the residue with water retained at a high temperature of 200 to 320 ° c . and a high pressure ; and recovering the resulting polyamine and / or polyol .