A battery includes a first insulator, a first electrode layer, and a first counter-electrode layer. The first counter-electrode layer is a counter electrode for the first electrode layer. The first insulator includes a first electrolyte portion, a second electrolyte portion, and a first bent portion. The first bent portion is positioned between the first electrolyte portion and the second electrolyte portion. The first electrode layer is disposed in contact with the first electrolyte portion. The first counter-electrode layer is disposed in contact with the second electrolyte portion. The first insulator is bent at the first bent portion, and thereby the first electrode layer and the first counter-electrode layer are positioned facing each other.