Abstract: A nonaqueous-electrolyte secondary battery is disclosed which is capable of maintaining satisfactory adhesiveness of leads of terminals of electrodes in heat-welded portions of a case of the nonaqucous-electrolyte secondary battery without deterioration of the moistureproofing characteristics. A battery element is accommodated in a case constituted by laminated film such that the battery element is encapsulated by heat welding. Leads of terminals of electrodes electrically connected with the electrodes which constitute the battery element are exposed to the outside portion of the nonaqueous-electrolyte secondary battery through heat-welded portions. Portions of the leads of the terminals of the electrodes corresponding to the heat-welded portions are coated with an olefine adhesive layer containing a titanate coupling material and a coating layer made of resin which is the same as resin which forms the innermost layer of each of the laminated films.