There is provided a method for highly treating distillation waste generated in the process of separating a distilled alcoholic material after alcoholic fermentation of starchy materials. The method includes the steps of adding sodium polyacrylate to the distillation waste from the starchy materials, then adding chitosan to treat the distillation waste, and further adding sodium polyacrylate to the waste. Furthermore, solid-liquid separation is then carried out. A liquid material thus separated is brought into contact with a reverse osmosis membrane.