Abstract: Disclosed herein is a silencer constituted by a casing, open at the lower extremity made to communicate with the source of compressed gases, and closed at the top by a cover, inside which are placed, from the bottom upwards, a first element, a filter and a second element which, jointly with the inner surface of the casing, define a first, a second and a third expansion chamber, respectively, for the compressed gases.The first expansion chamber communicates with the open extremity of the casing, the second contains the aforementioned filter, while the third, via a slit made in the cover, communicates with the outside. The first and second expansion chamber are inter-communicating because of through holes drilled in the first element, and likewise the second and third expansion chamber are inter-communicating because of through holes drilled in the second element.