PURPOSE: To constitute a fitting plate in which each unit of a punch and a die, of a structure by which it can be removed and installed easily from and to a frame of this press machine, and to execute various punch press working by changing those fitting plates themselves.

CONSTITUTION: In an opening side 1a of a frame 1 whose side face is roughly a C-shape, each unit of plural punches and dies is installed. Between each punch unit 7 and die unit 8 which are installed, a fitting plate 6 formed so that a stock to be worked can be inserted and detached and moved from the inside of the frame 1 is provided. The fitting plate 6 is freely slidable and fixable against the frame 1, and also, racked and installed so as to be freely separable and installable in its frame 1 by said slide. In such a way, a change of each die is not executed, and it can be changed together with the fitting plate 6 by a single operation, therefore, many kinds of working can be executed as labor saving by far in the same way as changing a die.