A manganese dry battery with excellent leak-proof property is provided, in which electrolyte leakage does not occur even if the size of a positive electrode material mixture is increased to meet a demand for improvement in discharge property. In a sealing part, a first circular projection, a second circular projection and a third circular projection are arranged at the bottom in sequence from the center to the outside, and a positive electrode carbon rod supporting part is provided in an innermost periphery portion to have an interval from the first circular projection. A groove between the first projection and the carbon rod is formed to have a substantially rectangular vertical section, kraft board is pressed by flat bottom surfaces of the first and second projections and an opening of the zinc can is fitted between the second and third projections.