A separator for an alkaline storage battery includes a plurality of polyolefin resins. The polyolefin resins include a first polyolefin resin that is sulfonated, and a second polyolefin resin that is sulfonated. The degree of sulfonation of the first polyolefin resin is different from that of the second polyolefin resin. Thus, a novel separator having high liquid retention properties and high air permeability, and an alkaline storage battery using the same can be obtained.