Experiments were carried out to confirm the theory that some heavy metal ions promote saccharification. Saccharification of peanut shells with 0.8 N HClO4 solution was carried out with the addition of one of Fe+++, Al+++, Cu++, Pb++ and Hg++, and the formation of monosaccharide and furfural was observed. Elimination of heavy metal ions from saccharifying solutions by electrolysis was also examined. It was found, from these experimental results, that the presence of heavy metal ions during saccharification had neither favorable nor adverse effect, although it was also found that these metallic ions were all quantitatively removed by electrolytic deacidification of acid saccharifying solutions.