Methods of effectively utilizing yeast-containing waste products generated after yeast use can be applied to absorbing agents, drying agents, soil conditioners, catalysts, and other common applications in the same manner as to charcoal-based materials of other materials by carbonizing the waste product, but a new search was needed in order to broaden the industrial utilization of these products. By supporting a particulate or powdered charcoal-based material obtained by carbonizing a yeast-containing material on an electrically conductive gas-permeable base, an electrode can be obtained that is capable of the electrochemical reduction of oxygen. The present charcoal-based material can provide new applications that have not been hitherto proposed, in the sense that oxygen can be electrochemically reduced smoothly and at a small overvoltage (resistance), and a large electromotive force can be obtained, by placing the charcoal-based material at the intersection of the ion path and the oxygen path.