The present invention provides a finishing machine (PT) of concrete surface (F) comprising a body (10) which supports a plurality of rotatable trowels (20) with a plurality of trowel blades (21) through radial support members so that the trowels (20) can revolve around the central axis (11) of the body (10), the body (10) being equipped further with a driving means (30) of the rotatable trowels (20), a power generator and a traveling means (17) of the finishing machine (PT) which is placed just below the central axis (11), wherein the driving means (30) of the rotatable trowels (20) is a gasoline engine (30), and wherein each rotatable trowel (20) is driven by a transmission shaft (33) branched off from a gearbox (31) and the angle between the surface of revolution of each rotatable trowel (20) and the concrete surface (F) is minutely changeable by using a means for angle adjustment (24). In view of improving the performance of the finishing work by the finishing machine of concrete surface (F) as much as possible and adapting the finishing machine (PT) to the nature and state of concrete to be treated, detailed construction of various elements of the finishing machine (PT) is also disclosed. The finishing machine (PT) of concrete surface (F) according to the present invention was accomplished for the purpose of solving the problems of the electric finishing machine in the prior art by replacing its electric motor with a gasoline engine (30).