PURPOSE: To uniformalize finishing conditions and the time required, by changing processes up to correction from measurement of eccentric load into automation wherein the eccentric load of a body of revolution, such as, a turbine shaft, etc. is measured, electron beams are irradiated to a portion where the eccentric load is concentrated and the load is compensated.

CONSTITUTION: A body 3, to which beams are irradiated, is revolved by means of a motor 1, and only a component 7 running parallel with a coupling rod 6' among the vibration of a bearing 5 is detected by means of a vibration dtector 6 consisting of a resistance with strain gauge, etc. The detecting output 8 is differentiated by means of a differentiator 12, and a portion of the maximum value of a vibration wave-form b, which becomes to zero, that is, a portion where the eccentric load of the body 3, to which the beams are irradiated, is concentrated is detected by the differentiation. The output 8c of said differentiation is supplied to an FF circuit 13, trigger signals 8d are formed, a synchronizer 14 is driven by the trigger signals 8d, and the trigger signals are applied to an electron gun 22 delaying preceeding distance 46 only by time when the body 3, to which the beams are irratiated, moves. The portion where the load is concentrated is removed by irradiating electron beams 24 generated to an irradiation point 47. The electron beams 24 are deflected by means of a deflecting coil 43 because the body 3, to which the beams are irradiated, shifts.