There is provided a battery containing an electrolyte, according to which oxidative decomposition of the electrolyte is suppressed. The battery contains a positive electrode having an active material and an electron conducting material. The electron conducting material has a barrier layer at least on the surface thereof. This barrier layer is substantially constituted from at least one material selected from (a) oxides of elements in group 2 to 14 and the third or subsequent period of the periodic table, (b) carbides of elements in group 2 to 14 and the third or subsequent period of the periodic table, (c) nitrides of elements in group 2 to 14 and the third or subsequent period of the periodic table, and (d) tungsten.