To obtain a sugar solution having an extremely reduced betaine content by purifying a beet leachate by a purifying method of combined chromatography and ion exchange resin treatment.

In this method for purifying a beet leachate comprising a preliminarily purifying process for removing a suspension and a polyvalent ion from the beet leachate to prepare a previously purified sugar solution, a chromatography purifying process for preparing a chromatography purified solution low in ratio of colored material and ionic substance to sucrose by chromatographing the previously purified sugar solution using water as an eluent and a desalting process for successively passing the chromatographically purified solution through at least a strongly acidic cation exchange resin bed and a basic anion exchange resin bed to give a desalted sugar solution, the chromatographically purified sugar solution is passed through a strong acid salt type strong basic ion exchange resin bed and is supplied to the desalting process.