NOVELTY - The storage battery has a spiral electrode group that is provided with a positive plate (2) and a negative plate (3) spirally wound with a separator (1), such that the separator including several sulfone group-containing regions, and the several sulfone group-containing regions are separated from one another in a winding direction, and placed to face the positive plate or the negative plate. The sulfone group-containing regions are placed between an outer periphery of the electrode group and a case storing the electrode group.    USE - Alkaline storage battery such as nickel-metal hydride storage battery and nickel-cadmium storage battery for use as power source in electric vehicle, hybrid vehicle, power-assisted bicycle and electric power tool.    ADVANTAGE - The alkaline storage battery is excellent in capacity retention performance even with a small size of sulfone group-containing regions. The boundaries are generated at only a portion of the electrode in the winding direction, so that the foregoing defects are hard to occur, and production is relatively easy. The sulfone group-containing region comes into proper contact with an electrolyte solution retained in a gap between the spiral electrode group and the battery case, so that nitrogen-based impurities dissolved in the electrolyte solution is effectively trapped. When the ratio of sulfone group-containing regions is 30% or less of the surface area of the sheet-shaped article, reduction of the strength of the separator is prevented, and deterioration of liquid retainability is prevented to improve cycle life performance.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for producing an alkaline storage battery.    DESCRIPTION OF DRAWING(S) - The drawings show a front view and a side view in an extended state of a separator and a method for producing a spiral electrode group using the separator.    Separator (1)    Positive plate (2)    Negative plate (3)    Layered product (10)    Subsidiary separator (11)