The invention relates to a method for reducing wobbling of a rotating rotor body (1) which is mounted in a freely suspended manner and which comprises reflecting surfaces (13) on the outer periphery thereof. According to the inventive method, a measuring beam (5) having a predetermined point of incidence is reflected by the rotating reflecting surfaces (13) of the rotating rotor (1) and are directed onto a position detector (17) after having been reflected. The signals of said detector are fed to a computer (22). The computer determines the difference between the largest and smallest value of the signals output by the position detector (17) during a complete rotation of the rotor body (1), as well as the angular positions of the rotor body (1) corresponding to said values, and calculates control signals therefrom for the correcting device (16). This causes a change in the distribution of mass on the rotor body (1) during the rotation or a subsequent rotation of the same. This change in the distribution of mass is effected in a manner which contactless and which does not have an affect on the reflecting surfaces (13) such that the subsequently determined difference between the smallest and largest value of the signals output by the position detector (17) is less than the difference determined during the previous rotation. The invention also relates to a device for carrying out such a method.