PURPOSE: To allow the forming work of either a front side or a rear side of a metal plate and to unnecessitate the change of die attaching to the machine each time a forming direction is changed.

CONSTITUTION: A punch 9 is attached movably only for a prescribed amount in the direction of the axial line on a punch head 5; and a cylindrical tool retainer 15 surrounding the outer circumference of the punch 9 is attached movably only for a prescribed amount in the direction of the axial line. Between the punch head 5 and the punch 9, an urethane rubber 19 is provided; and between the punch head 5 and a punch guide 15, an urethane rubber 21 is provided. Inside rugged crown members 25, 27 and outside rugged crown members 29, 33 are provided which selectively inhibit both the punch and the tool retainer corresponding respectively between the punch head 5 and the punch 9 and between the punch head 5 and the tool retainer 15 are relatively displaced in the direction mutually approaching the axial line.