Disclosed is an electrode which comprises: a conductive supporting body (11); and an active material layer (12) that is provided on the conductive supporting body (11) and contains an electrode active material (13) and a conductive assistant (14). The electrode active material (13) contains either a first polymer compound which has a tetrachalcogenofulvalene skeleton as a repeating unit of the main chain and/or a second polymer compound which is a copolymer comprising a first unit that contains the tetrachalcogenofulvalene skeleton in a side chain and a second unit that does not contain the tetrachalcogenofulvalene skeleton in a side chain. In the active material layer (12), the electrode active material (13) does not form particles and covers at least a part of the surface of the conductive assistant (14).