The expression Bearingless Axial-Force/Torque Motor refers to an electromechanical actuator, that permits the independent and concurrent generation of drive torques and axial levitation forces with only one (combined) stator winding system. The concentric non-overlapping air-core stator coils are shaped in circumferential rotor direction. Through interaction with a very specific permanent magnet rotor excitation system, the end-windings of the current-excited air gap winding produce axial directed Lorentz-forces to control the inherently unstable axial rotor position. The remaining two lateral and two tilting degrees of freedom of the rotors rigid body motion are stabilized by use of a passive magnetic suspension concept. Two axially staggered passive magnetic, repulsive ring bearing units provide radial resilience in radial direction without any electrical energy consumption, while destabilizing axial thrust is generated simultaneously. The present thesis covers the deduction of the theoretical framework, the electromagnetic actuator design, the physical system modeling and model-based control concepts for the brand-new bearingless drive concept. A qualitative analysis of the motor topology clarifies the interrelation between the number of rotor poles, the number of stator coils and the detrimental mechanical variables radial force, rotor tilting and drive torque ripple. The formal deduction of the active axial forces as a function of the electrical system variables requires the introduction of an additional zero sequence (common-mode) component in addition to the rotor excitation flux-oriented system equations of the synchronous machine. The model parameters for dynamic system simulation and control design are established based on available prototype measurements or from corresponding magnetostatic 3D-FEA results likewise. ^In presence of significant process disturbances and model uncertainties, the deduction of a stabilizing controller parametrization for inherently unstable plants, like the axial position dynamics of the Bearingless Axial Force/Torque Motor, is a quite challenging task. An advanced, frequency domain based control synthesis method can solve the mentioned stabilization problem. The resulting controller parametrization as an essential part of the closed-loop control complies with all the predefined design specifications and restrictions, while the overall system stability requirements are met simultaneously. Computational dead times, signal filtering delays and the saturation of the actuating variable are just a few of the frequently occurring side-effects in a real world digital control, that cause deviations from the ideal model behaviour. All of them are taken into account for stability analysis with the proposed computer-aided control design procedure. The uncertain plant parameter definition, the external disturbances and the design specifications are merged with the corresponding closed-loop control system equations into an extended numerical plant description. Based on this structure, the robust stability domain of the closed-loop control system under plant uncertainties can be predicted numerically making use of the robust control theorems. The application of the mu-analysis algorithms on the extended plant description of the axial rotor position dynamics yields an estimation of the robust stability bounds. A concise summary of the fundamentals and conclusions of the linear stability theory and the modern theory of robust control facilitates the interpretation of the calculated robust stability margins. The experimental verification of the bearingless drive concept is carried out by the construction and the measurement of two prototypes, which cover a large part of the realizable system topologies.