PURPOSE: To improve working efficiency of the secondary plate working, by joining plural secondary plates by superposing their ends together, and applying press working to form a unified work, and after performing working such as drawing, piercing etc., dividing into plural parts.

CONSTITUTION: Two secondary plates D are prepared. In the first process A, the end parts of the secondary plates D, D are superposed. Burring parts I, I and hemming parts H, H are formed on the superposed part D1, and the two are joined in a body to obtain a press work W. In the second process B, the press work W is pierced. In the third process C, the press work W is trimmed and divided into plural parts P, P, and placed on a part stand S. By this way, handling of the work becomes easy, number of workers M can be reduced, and the carrying device aligning in single row is obtained.