A battery electrode plate (19) is produced via an active material impregnation step for impregnating an entire porous core substrate shaped like a thin plate (1) with an active material (3), a pressing step for performing press working on the core substrate to form a plurality of rail shaped protrusions (8), an active material removal step for removing the active material to form core substrate exposed sections (13) by applying ultrasonic vibrations to the rail shaped protrusions, a flattening step for compressing the core substrate exposed sections down to an identical level with the other sections, and a cutting step for cutting predetermined sections including the core substrate exposed sections.