There is described in the specification a mercury-free manganese dry battery wherein the cathode mixture contains boric acid or an alkali borate at a ratio of 0.04 to 0.4 parts by weight per 100 parts by weight of manganese dioxide as a boron conversion value 2 or wherein the separator contains boric acid or an alkali borate at a ratio of 0.1 to 8.0 parts by weight per 100 parts by weight of a dry solid content in the pasting agent. Such battery performes excellent discharge properties under light loading conditions.