An electrolyte for driving an electrolytic capacitor comprising an organic solvent, at least one ammonium carboxylate and, at least one solute selected from the group consisting of quaternary ammonium borates and quaternary ammonium phosphates. An electrolyte further containing a polymer is disclosed. The polymer includes a polyether polyol represented by the following formula: ##STR1## where, 1.sub.1, 1.sub.2, 1.sub.3, m.sub.1, m.sub.2, m.sub.3, n.sub.1, n.sub.2, and n.sub.3 are positive integers, and 2.ltoreq.(1.sub.1 +m.sub.1).times.n.sub.1 .ltoreq.50, 2.ltoreq.(1.sub.2 +m.sub.2).times.n.sub.2 .ltoreq.50 and 2.ltoreq.(1.sub.3 +m.sub.3).times.n.sub.3 .ltoreq.50, andR.sub.1, R.sub.2 and R.sub.3 independently represents a hydrogen atom, which may be substituted one another by the same or different isocyanate residue or acrylic residue, wherein each end of the isocyanate residue or acrylic residue may be three-dimensionally linked.