To prevent resonance by performing a digital filter process at a sampling frequency, and controlling an electromagnet based on a signal having a damped frequency range including a resonance frequency of a natural frequency and a rotation frequency that varies according to rotation speed.

A rotation sensor 8 and a rotation speed monitor portion 43 detect rotation speed of a rotor 1, a sampling frequency determining portion 44 changes sampling frequency with variation of the rotation speed, and a displacement sensor 2 and an A/D converter 3 detect displacement of the rotor 1. Based on a digital displacement signal based on this, a magnetic bearing control portion 41 performs a predetermined digital filter processing at a sampling frequency, changes cut-off frequency according to the sampling frequency, outputs a control signal having a damped frequency range including a resonance frequency of a natural frequency and a rotation frequency that varies according to the rotation speed of the rotor 1, and controls an electromagnet 7 of the magnetic bearing through a D/A converter 5 and an amplifier 6. Therefore, resonance signals are removed and the resonance can be prevented.