NOVELTY - The carrier insert comprises a spatial web made of staple fibers using the hosiery method. The spatial web has internal textile units (11, 12, 13, 14) that join each other in intermediate complete nodal points (20) with an adhesion and/or cohesion and/or hosiery joint and are situated between the complete nodal points, and external textile units (17) situated along the edges of the web. A part of the complete nodal points is an even number of internal textile units guided into the given complete nodal point.    USE - The carrier insert is useful for accommodating and maintaining the bio film culture of fluid cleaning structures, and for sewage treatment plants using biofilm.    ADVANTAGE - The carrier insert is easy and economical to produce, operate and maintain, can be easily and safely fitted in the reactor during use, eliminates the risk of blocking up, and avoids the damage in the nodal points because of the forces deriving from fastening after a long period of operation.    DETAILED DESCRIPTION - The carrier insert comprises a spatial web made of staple fibers using the hosiery method. The spatial web has internal textile units (11, 12, 13, 14) that join each other in intermediate complete nodal points (20) with an adhesion and/or cohesion and/or hosiery joint and are situated between the complete nodal points, and external textile units (17) situated along the edges of the web. A part of the complete nodal points is an even number of internal textile units guided into the given complete nodal point. The internal sides of the external textile units situated along the edges of the web are connected to a complete nodal point. Each external sides of the external textile units are provided with connection points for joining the structure. The web is attached to the structure in a fixed position via the connection points. The two of the internal textile units situated in a given complete nodal point are positioned in the same principal plane. The principal plane is taken through the complete nodal point. Some of the textile units are made of the same material. Individual groups of such arranged textile units form a main body. The connection points are situated at the ends of the main bodies, at the ends of the main bodies and on the free sections between the ends of the main bodies. The distance (T) between the neighboring complete nodal points is 100-150 mm. A part of the textile units contains longitudinal free fibers (30) and cross fibers (40) connecting the longitudinal free fibers to each other. The distance between two neighboring longitudinal free fibers is maximum 50 mm. The distance between two neighboring cross fibers is maximum 50 mm. The cross-section of the longitudinal free fiber is 0.0001 mm2.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a carrier insert.    Internal textile units (11, 12, 13, 14)    External textile units (17)    Complete nodal points (20)    Longitudinal free fibers (30)    Cross fibers. (40)