The essence of the invention is that it involves the feed of a material to be ground and the acceleration of said material. During acceleration, jets are formed from a mixture of material to be ground and air and said mixture is fed to an annular grinding chamber. Simultaneously, a stream of air is fed into the grinding chamber in a direction contrary to that of the mixture jets. Local cyclic variations in the pressure and rate of the air stream and/or in the pressure and rate of the mixture jets are formed along the perimeter of the grinding chamber. The finished product is removed. The material grinding device comprises a housing with a unit for the feed of the material to be ground and a unit for the removal of the finished product. An annular grinding chamber is accommodated in the housing. Two rotating rotors with the blades fastened thereto are coaxially arranged in the housing. The blades for accelerating the material to be ground and feeding said material into the grinding Chamber and/or the blades for feeding air into the grinding chamber are arranged at varying intervals.