An electron conductive high polymer is described, having at least a repeating unit represented by following formula (1); ##STR1## wherein X.sub.1 and X.sub.1 ' each represents a divalent linkage group; R.sub.1 and R.sub.1 ' each represents an alkylene group; R.sub.2 represents a cyclic ester derivative group, an acyclic ester derivative group, a cyclic ether derivative group, or a sulfone derivative group; R.sub.3 represents a hydrogen atom, an alkyl group, an aryl group, a cyclic ester derivative group, an acyclic ester derivative group, a cyclic ether derivative group, or a sulfone derivative group; a, b, and c each represents 0 or 1; and Y represents --NR.sub.4 --, --O--, --S--, --Te--, or --Se--wherein R.sub.4 represents a hydrogen atom, an alkyl group, or an aryl group. A positive electrode for battery using the electron conductive high polymer is also described.