Abstract: A method for vibratory treatment of workpieces involves repeatedly exiting a workpiece at its resonant frequencies of various harmonics by an unbalance vibration exciter connected to an electric motor. The race of one of the bearings of the motor armature is electrically insulated from the electric motor frame. The e.m.f. value of the bearing is measured continuously. Once the natural frequency of the workpiece being treated has been shifted as a result of the vibratory treatment performed, a change in the e.m.f. value is recorded and, after the natural frequency has been stabilized, the vibration exciter is retuned to the shifted value of the resonant frequency. The vibratory treatment is carried out on each harmonic until stabilization of the resonant frequency, at which time vibratory treatment on another harmonic is made. Multiply repeated vibratory excitation procedures on each of the harmonics are performed until a resonant frequency is reached, at which the e.m.f. value varies no longer.