PURPOSE: To regenerate a high purity sulfuric acid from a waste sulfuric acid discharged from a production process or the like of a semiconductor device and to recycle the product electrolyzing the waste sulfuric acid with a multi- chamber type electrolytic cell or a two chamber type electrolytic cell.

CONSTITUTION: The waste sulfuric acid is supplied into a cathode chamber, which consists of a cell wall and an anion exchange membrane of the multi- chamber electrolytic cell divided into the multi-chambers of ≥3 chambers with at least one anion exchange membrane and at least one cation exchange membrane, or into a cathode chamber 23 of the two chamber electrolytic cell 21 divided by an anion exchange membrane 22 and is electrolyzed. And sulfuric acid obtained in a middle chamber formed by the anion exchange membrane and cation exchange membrane of the multi-chamber type electrolytic cell or in an anode chamber 24 of the two chamber type electrolytic cell is electrolyzed in an anode chamber formed by the cation exchange membrane and cell wall of the multi-chamber type electrolytic cell or in an anode chamber 28 of the two chamber type electrolytic cell divided by a cation exchange membrance 26 and an oxidative material is formed together with concentration of sulfuric acid.