A bipolar electrode includes a collector; a positive electrode active material layer disposed on one surface of the collector; and a negative electrode active material layer disposed on the other surface of the collector. The quotient of the volume resistance of the collector and that of the positive and negative electrode active material layers is between 10−3 and 104. The bipolar electrode further includes a current distribution relaxation layer having a volume resistivity lower than that of either the positive electrode active material layer or the negative electrode active material layer. At least one active material layer having a volume resistivity larger than that of the current distribution relaxation layer is disposed between the current distribution relaxation layer and the collector.