In an alkaline battery including a cathode mixture including gamma-manganese dioxide and lambda-manganese dioxide, an anode, and an alkaline electrolyte, the weight ratio of the lambda-manganese dioxide to the gamma-manganese dioxide is set to 0.5/100 to 4.5/100, and the average particle size of the lambda-manganese dioxide is set to 3 to 10 μm. An alkaline battery excellent in high-load discharge performance without decline in low-load discharge performance is provided.