PURPOSE: To obtain the subject high-purity saponin excellent in workability and useful not only for foods but for cosmetics in high yield by removing high- molecular components by ultrafiltration and then recovering the objective saponin by centrifugation.

CONSTITUTION: Crushed beet materials are extracted using water or an aqueous alkaline solution and the resultant extract is subjected to ultrafiltration to remove high-molecular components. The pH thereof is lowered using a mineral acid until flocks of beet saponin are formed and the resultant flocks are recovered by the centrifugal separation, thus obtaining the objective saponin. In addition, the recovered saponin is preferably dissolved in remarkably weak alkali solution and the obtained solution is passed through a synthetic adsorption resin to adsorb beet saponin onto the above-mentioned resin. The adsorbed saponin is subsequently eluted using a solvent.