Technical feasibilities of a Fenton-type reaction of cuprous ion (Cu + ) with hypochlorous acid (HOCl) and an electrochemical Fenton-type process using this reaction were discussed in this research. Since 1,4-dioxane was decomposed by mixing Cu + and HOCl, it was inferred that the reaction of Cu + + HOCl → Cu 2+ + ·OH + Cl − happened. As a result of electrolyzing 1,4-dioxane solution containing cupric ion (Cu 2+ ) and chloride ion (Cl − ), 1,4-dioxane was decomposed with the current efficiency (η) of 6.1%, which was higher than that for control experiments (1.7 − 1.8%). Therefore, it was confirmed that the electrochemical Fenton-type process with the cathodic reduction of Cu 2+ to Cu + and the anodic oxidation of Cl − to chlorine was feasible. The effect of current density on the electrochemical Fenton-type process was discussed by a series of experiments. Although 1,4-dioxane removal rate was enhanced with the increase in current density in the range of 2.5 − 10 mA/cm 2 , the η did not depend on current density clearly. Since deposition and precipitation of copper during electrolysis were thought to affect the η, it will be required to develop a technique avoiding the deposition and precipitation of copper in the future.