A process for purifying a hydrogen peroxide solution is disclosed, comprising treating a 10 to 60% by weight hydrogen peroxide solution having a pH between 1.5 and 5.0 and containing anionic impurities with a hydrogencarbonate type or carbonate type anion exchange resin while adding an acid or a salt thereof having an acid dissociation constant pKa in water of not more than 5 to the hydrogen peroxide solution to be treated continuously or semi-continuously in an amount of from 0.5 to 5 milli-equivalents per liter of hydrogen peroxide solution. The hydrogen peroxide decomposing activity of the anion exchange resin can be inhibited without decreasing a rate of removal of strong acid radicals in the anionic impurities thereby minimizing oxygen evolution due to decomposition of hydrogen peroxide.
