To improve a yield when right and left forming parts of a product are formed from one plate material to be pressed by press-molding.

As a cutting line which is set on a press plate material 1 to be pitch-conveyed, a common cutting line α is determined which extends along a conveyance direction in a central region in a width direction of the press plate material 1 to become a boundary line of a left side product material part 11 and a right side product material part 12. A left side product forming part 10 corresponding to the left side product material part 11 is previously cut and removed from the press plate material 1. After this, a right side product forming part 20 corresponding to the right side product material part 21 is cut and removed from the press plate material 1.