A cutter unit for a rotating tilling machine comprises a coupling flange connected to a rotor, a first blade and a second blade that comprises a respective operating portion and a respective coupling portion. The cutter unit further comprises a housing seat for the blades. The coupling portion of the first blade comprises an opening suitable for housing a locking element for locking said first blade in a direction of extraction of the blades from the housing seat and the blades comprise a respective shaped portion.
