An alkaline battery having excellent discharge characteristics and higher discharge capacity with an increase in its internal resistance being suppressed is disclosed. The alkaline battery has a positive electrode active material which comprises primarily manganese dioxide and electroconductive carbon material. The electroconductive carbon material comprises expanded graphite particles having an average particle size in the range from 0.5 to 15 .mu.m, and the content of the expanded graphite particles is in the range from 2 to 8% by weight based on the solids in the positive electrode active material.