This invention relates to a shredding device having a driving unit driving a rotor including shredding tools on its periphery which for comminuting a material such as waste material and/or industrial residues, interact with a least one counter knife assembly that is arranged in a stationary fashion with respect to the machine housing during the shredding operation. The shredding device is characterized in that the counter knife assembly includes at least two counter knife bars which run approximately parallel to each other and are arranged one above the other in the rotating direction of the rotor, the counter knife bars, for the compensation of wear at the shredding tools and/or at the counter knife assembly, being arranged for an adjustment radially to the rotor axis by a mutually different degree by means of an adjustment device. A process for operating a shredding device is also described.