A monolithic honeycomb element includes a collection of adjacent ducts of mutually parallel axes separated by walls made of a porous material, the element having, in transverse cross section, a polygonal, notably quadratic cross section delimited by exterior wall elements, wherein at least one corner of the polygon, has, along the bisector of the angle at the corner, an additional thickness, such that the total thickness of the external wall, likewise measured along the bisector of the angle at the corner, is greater than the mean thickness of the exterior walls by a factor of at least 1.43, the additional thickness being obtained at least in part by an additional quantity of porous material on the external face of the corner.

A silicon carbide honeycomb filter constituted by honeycomb segments each comprising cell walls forming cells defining pluralities of flow paths, plugs sealing end surfaces of the cells alternately in a checkerboard pattern, and an outer peripheral wall, bonding material layers filling lattice gaps between the honeycomb segments for bonding them, and a skin layer enclosing the bonded honeycomb segments, the lattice gaps being provided with a bonding-material-free region extending in four directions from a center intersection to adjacent intersections, wherein the center intersection is an intersection located at the center axis of the honeycomb filter or its nearby position, among the intersections of the lattice gaps.