A battery such as a lithium secondary battery having a structure permitting reduction in both weight and thickness, wherein a groove for drying the solvent used for manufacturing the battery is provided in an electrode, thereby improving the productivity of the battery. Specifically, a battery composed of a positive electrode, a negative electrode and an electrolyte holding layer, characterized in that a solvent evaporation groove (11c) is formed in at least one of the positive electrode and the negative electrode, for example, in the positive electrode (11).