Abstract: The present invention provides a finishing machine for a concrete surface comprising a body which supports a plurality of rotatable trowels with a plurality of trowel blades through radial support members so that the trowels can revolve around the central axis of the body, the body being equipped further with a driving device of the rotatable trowels, a power generator and traveling rollers of the finishing machine which is placed just below the central axis, wherein the driving device of the rotatable trowels is a gasoline engine, and wherein each rotatable trowel is driven by a transmission shaft branched off from a gearbox. The angle between the surface of revolution of each rotatable trowel and the concrete surface is minutely changeable by an angle adjustment mechanism.