PURPOSE: To provide a mercury-free manganese dry battery which restrains increase in internal resistance during preservation or during a discharge under a light or medium load and also restrains a pulse discharge characteristic from being deteriorated by the increase.

CONSTITUTION: Zinc or a zinc alloy serving as a negative electrode 1, and a mix 3 serving as positive active material are opposed to each other with a separator 2 therebetween. A bismuth compound 14.8 to 0.2 microns in average grain size is attached to the surface of a separator material, the ratio of the amount of the attached bismuth to the surface area of one side of the separator being 0.01mg/cm2 to 0.17mg/cm2. A mercury-free manganese dry battery can be obtained with the internal resistance of the battery restrained from rising during preservation or during a discharge under a light or medium load so that a pulse discharge characteristic is not deteriorated.