An apparatus (3) retains bladed rotor disks (4, 6, 9) of a jet engine which engine includes an axial-flow compressor with several bladed rotor disks (4, 6, 9), at least one turbine section, at least one shaft and at least one tie-rod (12, 47), with at least two bladed rotor disks at the compressor inlet side (2) being designed as blisks (6), each being a single component integrally combining a rotor disk and circumferentially distributed rotor blades (5). So that apparatus for the retention of blisks can easily be mounted and demounted, the blisks (6) are releasably retained via the tie-rod (12, 47) and the other rotor disks (4, 9) are firmly attached to each other separately and independently of the tie-rod (12, 47).