An alkaline battery including a positive electrode, a negative electrode and an alkaline electrolyte, wherein the positive electrode includes a positive electrode material mixture including nickel oxyhydroxide, electrolytic manganese dioxide and expanded graphite, the expanded graphite has an average particle diameter on a volume basis of 5 to 25 μm, a BET specific surface area of 4 to 10 m2/g, and a bulk specific gravity (apparent density) measured by a static method of 0.03 to 0.10 g/cm3, the nickel oxyhydroxide has an average nickel valence of not less than 3.05, and a content of the expanded graphite in a total amount of the nickel oxyhydroxide, the electrolytic manganese dioxide and the expanded graphite that are included in the positive electrode material mixture of 3 to 15 wt %.