Abstract: A turbo-drill is provided with a mechanism for reducing the speed of rotation of the drilling bit, the mechanism being made in the form of a frictional reduction means wherein the rotors of the turbo-drill are the inner wheel and the stators of the turbo-drill are the outer wheel. Between the stators and rotors in the carrier of the reduction means disposed are bodies of rolling, which roll during rotation of the rotor under the action of contact frictional forces. In addition, between the reduction stages of the turbine and above them mounted are one or more auxiliary stages of the turbine, each having two wheels provided with vanes, one of the wheels being connected through its hub to the shaft so as to enable axial displacement thereof with respect to the shaft.