An object of the present invention is to provide a battery which is high in capacity density and superior in stability. An electrode containing a compound having a diazine-N,N'-dioxide structure shown by a general formula (1) described below as an electrode active material is used, ##STR00001## where x, y, x', and y' independently shows integer numbers of 0 or more respectively, and the order of condensation of diazine rings and benzene rings may be alternate or random. One of substituents R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.a, R.sub.b, R.sub.c, and R.sub.d shows a part of main chain or side chain of oligomer or polymer, and the other independently shows hydrogen atom, halogen atom, or a specific group.