The device, which serves for processing flat products, particularly separated sheets of paper, includes a device body that is holding a tool, with which the flat products can be processed. The inventive device further includes a tool bearing that is connected to the device body and that includes at least one bearing drive unit, a control unit controlling the bearing drive unit, a tool drive unit and a modular tool unit that includes said tool and that can be actuated by the tool drive unit when it is coupled to the tool drive unit, wherein the modular tool unit is releasably held by the tool bearing and is movable by the bearing drive unit towards the tool drive unit under the control of the control unit until it is coupled with the tool drive unit.