Abstract: Process for producing a filtering structure, in particular for cigarette filters from a fibrous mass comprising a homogeneous mixture of fibres of different types. Some of the fibres are necessarily thermofusible synthetic fibres having a low melting point and adhesive properties in the molten state, and the others are absorbent with respect to harmful products of tobacco smoke and stable at the melting temperature of the thermofusible fibres. The fibrous mixture is shaped into a cylindrical rod which is in state which is not yet coherent but homogeneous and comprises fibrous networks which are closely imbricated relative to each other.