PURPOSE: To save time and labor, by blanking simultaneously the lower half of the tail gate material from a steel plate for the part to be blanked for forming a door fitting part and upper half symmetricaly divided material from a steel plate between outside panel mterials.

CONSTITUTION: Outer side panel materials 2 of an automobile body are blanked successively from a steel plate 1 while feeding the beltlike steel plate 1 by standard size in the longitudinal direction. At this time, lower part divided materials 13, 13' for the tail gate that form symmetrically divided parts of the lower half of a tail gate material 8 of an automobile body is blanked from a part of the steel plate 1 corresponding to the blanked part for forming a door fitting part of the outer side panel material 2. At the same time, upper part divided materials 14, 14' for the tail gate that form symmetrically divided parts of the upper half of the tail gate material 8 is blanked from the steel plate 1 between the outer side panel materials 2.