A method of manufacturing a battery electrode material in slurry form to be coated on a sheet-shaped current collector, the battery electrode material containing an electrode active material made of electrolytic manganese dioxide (EMD) and containing an aqueous binder. The method includes, as a process of mixing and kneading raw materials of the battery electrode material by using water as a solvent, mixing the electrode active material; mixing the binder; and mixing a neutralizing agent, the neutralizing agent being lithium hydroxide (LiOH).