A method for manufacturing a positive electrode plate for a non-aqueous secondary battery including: preparing an active material A, a conductive material B, a binder C, a thickener D, and a liquid component E, the thickener D being in a powder state, the conductive material B including a carbon material, the thickener D including a water-soluble polymer, and the liquid component E including water; preparing a slurry including the component E and an electrode material mixture, the material mixture including the active material A, the conductive material B, the binder C, and the thickener D; and applying the slurry on a current collector. In preparing the slurry, the thickener D in a powder state, the active material A and the conductive material B are kneaded together with the liquid component E, and then the primary kneaded matter, the binder C, and an additional liquid component are kneaded.