Abstract: The silencer combined with a catalytic converter comprises a housing including an inner tubular element in which a catalytic converter is fitted. The engine exhaust gases enter into the silencer through a venturi nozzle, flowing through a series of diaphragms made of porous ceramic material treated with catalytic materials, and flow out from an exhaust outlet of the silencer depleted of pollutants. The ceramic diaphragms may be cup shaped and provided with through-holes or ogive shaped with perforated walls and they may consist of elements formed by a plate provided with lateral flanges forming opposite cavities. The elements may be combined with one another in different manners to form a sequence of chambers with shape and volume best suited for each type of engine.