To suggest a manufacturing method for a steel wheel disk for an automobile, which improves design, and reduces weight and cost.

A steel plate 20A having a hub hole reference point 21 to form a hub hole 3 is punched so that punching section 25 may be perpendicular to a plate surface of the steel plate 20A and a plurality of heat radiation base holes 9a are formed in a peripheral direction with the hub hole reference point 21 as a center. Subsequently, a steel plate 20B formed with the heat radiation base holes 9a is curved and a space between each of the heat radiation base holes 9a is projected in relation to an inner peripheral edge of each of the heat radiation base holes 9a, to obtain a spoke part 11. Thus, a metallic mold structure is simplified by punching a uniform flat plate. Generation of plate recess is prevented to improve designability and strength. As a result, thinning is promoted, weight is reduced, and manufacturing cost is lowered as a whole.