high - purity maltose is produced by applying a feed starch sugar solution with a maltose content of at least 70 % to a column packed with a strongly - acidic cation exchange resin of alkali metal - or alkaline earth metalform ; fractionating the feed solution by charging water thereto in a high - dextrin fraction , a high - dextrin . maltose fraction , a high - maltose fraction , a high - maltose . glucose fraction , and a high - glucose fraction , in the given order ; and recovering the high - maltose fraction . this process constantly provides a fraction with a maltose content of 93 % or higher , and enables industrial - scale production of a high - purity maltose much easier and at lower - cost than conventional processes .