Abstract: The present invention provides a method for manufacturing a steel plate-shaped component which can increase the yield and the working efficiency. When a steel plate-shaped component (1) such as a pole parking is manufactured, a steel disk-shaped initial material (10) is vertically placed in a cavity (41) of a dice (40) of a cold forging die so that the thickness direction of the initial material (10) is perpendicular to a pressing direction. The initial material (10) is pressed through cold forging against the peripheral side portion (11) by a punch (42) while the initial thickness of the initial material (10) is maintained substantially as it is, whereby an approximate component (20) approximating the plate-shaped component (1) is obtained. Subsequently, a margin portion (25) of the approximate component (20) is removed, whereby a half-finished product (30) is obtained.