The sealed alkaline storage battery of this invention includes a nonsintered nickel positive electrode using, as an active material, manganese-containing &agr;-nickel hydroxide including, as a solid-solution element, 15 through 50 wt % of manganese on the basis of a total amount of nickel and manganese; a negative electrode; and an alkaline electrolyte including 0.55 through 0.80 g of water per gram of the manganese-containing &agr;-nickel hydroxide. In this manner, the invention provides an alkaline storage battery exhibiting high positive electrode active material utilization for a large number of charge-discharge cycles.