An optimal robust vibration control of a rotor supported magnetically over a wide angular speed range is presented in the paper. The laboratory stand with the high speed rotor (max. 24000 rpm) was designed. The wide bandwidth controller with required gain, which is necessary to stabilize the structurally unstable and active magnetic bearing system was computed. For controller design, the weighting functions putted on the input and output signals were chosen. For control design, the dynamics of the rotor and uncertain parameters were considered. The optimized control system by minimization of the H norm putted on transient process of the system was presented. The robust controller was designed with considered asymmetrically magnetic bearings, signal limits and power amplifiers dynamic. The success of the robust control is demonstrated through computer simulations and experimental results. Matlab-Simulink was used for the numerical simulation. The experimental results show the effectiveness of the control system as good vibrations reducing and robustness of the designed controller in all dynamic states.