Detachable front attachment unit (10) for a maize chopper (20), having a bottom part (12) comprising a cutting device (121) for cutting down maize plants, and a top part (13) which is arranged above the bottom part and comprises a separating device (131) for separating the maize ears from the stem. The front attachment unit (10) comprises an intermediate frame (15) which comprises first fastening means (153) for attaching the bottom part (12) and second fastening means (151) for attaching the top part (13) to the intermediate frame (15). The bottom part is detachably attachable to the intermediate frame by means of the first fastening means (153), so that the bottom part can be used for the maize chopper both separately and in an integrated manner.
