A polyether rubber comprising units expressed by the following general formula (1) in 0.1 mol % or more but less than 30 mol % is provided. (wherein in the above general formula (1), A+ is a group which contains a cationic nitrogen-containing aromatic heterocyclic ring. Said group which contains a cationic nitrogen-containing aromatic heterocyclic ring is bonded with the carbon atom at the “2” position which is shown in the above general formula (1) through a nitrogen atom which forms said cationic nitrogen-containing aromatic heterocyclic ring. X− is arbitrary counter anion.)