A method of reduction reclamation of an oil or prevention of oxidation degradation of the oil of the present invention includes: using an electrolytic cell 13 having an anode 11 and a cathode 12 made of a hydrogen storage material, and inside of the cell divided by the cathode 12 into an electrolytic chamber 13A and a reduction chamber 12A; supplying the oil to the reduction chamber 12A while applying an electric voltage between the anode 11 and the cathode 12 to electrolyze an electrolytic solution supplied to the electrolytic chamber 13 (Translator's comment: correctly, 13A); and absorbing hydrogen generated on the cathode 12 in the electrolytic chamber 13A in the cathode 12 to reduce the oil in the reduction chamber 12A, the method for reduction reclamation of the oil or prevention of oxidation degradation of the oil allowing continuous treatment.