The present invention provides a bio-electrode composition including a silsesquioxane bonded to a sulfonimide salt, wherein the sulfonimide salt is shown by the following general formula (1): wherein R1 represents a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms that may have an aromatic group, an ether group, or an ester group, or an arylene group having 6 to 10 carbon atoms; Rf represents a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms containing at least one fluorine atom; M+ is an ion selected from a lithium ion, a sodium ion, a potassium ion, and a silver ion. This can form a living body contact layer for a bio-electrode that is excellent in electric conductivity and biocompatibility, light-weight, manufacturable at low cost, and free from large lowering of the electric conductivity even though it is wetted with water or dried.