An object is to provide a process for producing a compact lithium ion secondary battery which exhibits high and stable performance and can take an arbitrary shape such as a thin shape. A process for producing a battery comprised of a positive electrode (1), a negative electrode (4), a separator (7) and an electrolytic solution comprises applying a binder resin solution mainly comprising a fluorocarbon resin or polyvinyl alcohol to a separator (7), laying a positive electrode (1) and a negative electrode (4) alternately on the separator (7) to form a laminated battery body having a plurality of laminates (12), drying the laminated battery body under pressure to form a tabular laminated battery body, and impregnating the tabular laminated battery body with an electrolytic solution.