PURPOSE: To revover impurities by contacting urea and a liquid phase org. substance at a specific temp. to adhere said impurities to urea.

CONSTITUTION: In recovering impurities from a liquid phase org. substance containing said impurities mixed therein, said liquid phase org. substance is contacted with solid or liquid phase urea alone or an urea mixed substance, that is, a mixture of urea and an org. substance such as a white clay, a metal powder or a carbon type material or a woody material, a fiber material or a synthetic resin as a filter material or a precipitation promoting material at a temp. not exceeding a decomposition temp. of said liquid phase org. substance and urea, that is, a temp. of up to 132°C as an upper limit to adhere impurities to urea or the urea mixed substance. Subsequently, said impurities are rapidly filtered out or precipitated to be recovered. In using urea as a filter material, said urea is used in a solid form, that is, it is used by impregnating in a particulate, a powdery of a fibrous material and, in promoting precipitation of floated substances or precipitates, a water containing liquid or a polyhydric alcohol liquid or a liquid phase org. substance is heated to use a small amount of water as a viscous material or a liquid with urea.