to fig1 thereof there is seen a diagrammatic illustration of a basic construction of an exemplary embodiment of a honeycomb body 1 according to the invention with structured sheet metal layers 2 as a major constituent part in which the structured sheet metal layers extend approximately concentrically around a geometric central axis 4 and each individually approximately have the shape of a funnel a cylindrical cavity 5 is situated in the interior of the honeycomb body the structured sheet metal layers 2 are delimited at the outside by an outer lateral surface or jacket surface 6 fig2 shows a diagrammatic longitudinal section through the geometric central axis 4 of fig1 in this case it can be seen that numerous channels 7 lead obliquely outward from the cavity 5 specifically with a cone angle a with respect to the direction of the geometric central axis 4 wherein all of the channels end at the outer lateral surface 6 in this way a conical side face 11 and a hollow conical side face 10 are formed fig3 shows once again in a diagrammatic illustration a perspective view of a single structured sheet metal layer 2 which extends in funnel shaped form around the cavity 5 in this case it is also possible to see the particular channel shape selected in this exemplary embodiment which is shown in more detail in fig4 fig4 illustrates the general geometric problem in forming from substantially planar sheet metal strips structures which have the same structure height h over the entire width of the sheet metal strip but despite the same amount of material being used around the perimeter have a smaller cross section at one end than.