The possibility of using the acoustic emission method for monitoring the cutting process mode is considered. The influence of mechanical chatter in the technological system on the parameters of acoustic emission signals has been experimentally revealed. It is established that a short-term drop in the acoustic emission spectral power is observed in the transition from a steady to a chatter cutting regime. In the region of high-amplitude vibrations, the time dependencies of median frequency of the AE decreases, while that of the spectral power increases sharply.