Abstract: An improved stopper structure for a storage battery container according to the present invention is basically defined as a unit including a plurality of hollow stopper supports which comprise threaded support, a spongy rubber, and a rubber pad within each hollow stopper support. Each stopper support has a cylindrical shape with a hollow center to accomodate the abovementioned elements, respectively. The gas that evolves during battery operation is blocked by a stopper, additionally, the water vapor has no way to escape, therefore, the amount of battery fluid loss is reduced. At a time that the evolved gas within the hollow stopper support possesses enough pressure, the rubber pad will be forced to curve upwardly. As a result, the gas may be evolved along a slot provided across the bottom surface of a trough carrying the stopper supports.