An alkaline storage battery comprises: a positive electrode plate; a negative electrode plate; a separator; and an alkaline electrolyte retained by the positive electrode plate, the negative electrode plate, and the separator, wherein the separator has a large number of pores, such that a total volume A of the pores (per unit mass; cm³/g) is in the range of 1A5, and the ratio of the volume B of pores having a diameter of 100 m or more (per unit mass; cm³/g) to the total pore volume A is in the range of 7%B/A20% (i.e., B/A is between 0.07 and 0.2).