A compacting machine 20 comprising a compaction chamber connected to introduction means 11 arranged to forcedly introduce a predetermined quantity of material to be compacted into the compaction chamber by conferring on the material a substantially rotary movement, wherein - the compaction chamber is substantially cylindrical and comprises circular plates 2 positioned at the ends of the compaction chamber and acting as end walls of the compaction chamber, the circular plates 2 being made to rotate about an axis perpendicular to the circular plates 2 and being arranged to at least partly close the compaction chamber laterally, the compaction chamber having a lateral surface defined and bounded by longitudinally disposed perimetral rollers 3 each rotatable about its axis, wherein engagement grooves are provided at the ends of the perimetral rollers 3 in correspondence with the end walls of the compaction chamber and wherein the circular plates 2 have an edge engaged in the engagement grooves of the perimetral r
