An adhesive for batteries a solution of which has improved wetting properties, which affords improved adhesive strength and prevents deterioration of battery performance, and which can provide secondary batteries having an arbitrary shape, such as a thin shape, with high reliability and high charge and discharge efficiency, and a battery using the same are disclosed. An adhesive comprising a thermoplastic resin, a solvent capable of dissolving the thermoplastic resin, and a neutral and aprotic surface active agent is used as an adhesive for batteries for adhering an active material layer joined to a current collector to a separator, whereby a secondary battery which can take an arbitrary shape, such as a thin shape, with high reliability and high charge and discharge efficiency can be obtained.