A production method for a separator-including electrode plate includes a step of forming an undried active material layer on a current collector foil, a step of forming an undried separator layer on the undried active material layer by applying a polymer solution containing a water-soluble polymer, water and a high-boiling point solvent, and a step of forming the porous separator layer by vaporizing the high-boiling point solvent after depositing the water-soluble polymer in the shape of a three-dimensional network by vaporizing the water contained in the undried separator layer, and forming the active material layer by vaporizing the dispersion medium contained in the undried active material layer.