Abstract: The punch unit comprises a punch driver connected with a punch which on its back end has a base. Furthermore, safeguarding members which keep the punch and the punch driver free of relative rotation during the stroke of the punch, and a pre-loaded compression spring which during the stroke of the punch can be compressed between the base and a guide bushing receiving the punch so that it cannot be rotated, but is axially displaceable, are part of it. To obtain a simpler and quicker assembly and disassembly of the punch it is provided that the pressure spring is maintained under pre-load in the guide bushing which is embodied as one or several pieces. A catch releasably supported on the rear end of the guide bushing and releasably engaging a recess, open toward the back, in the circumferential surface of the punch driver head prevents the punch driver head from jumping toward the back out of the guide bushing.