So that a staple driver does not perform a movement relative to a staple holder until the staple holder comes down on the material to be stapled, provision is made according to the invention for the staple holder and the staple driver of a stapling head to be driven by a common drive device via a cam control mechanism. The cam control mechanism has a cam plate which is made to perform a stroke movement via a drive pin on which it is rotatably mounted. The staple holder and staple driver are driven by two connecting rods which relative to the rotation axis act eccentrically on two sides on the cam plate. A stationary guide rail, against which the cam plate is supported with a guide surface during a first phase of the working stroke, prevents a rotary movement of the cam plate during the first phase of the working stroke and thereby fixes the staple driver relative to the staple holder.