Abstract: The honeycomb structured body of the present invention is a pillar-shaped honeycomb structured body having a honeycomb structure that a number of through holes are placed in parallel with one another in the length direction with a wall portion interposed therebetween and one of ends of each through hole is sealed, wherein a relation between a volume Y (L) of said honeycomb structured body and an aperture ratio X (%) on an inlet side satisfies the following inequality (1): Y??1.1X+68.5 (wherein Y?19, 35?X?56)??(1).

Abstract: A honeycomb filter for purifying exhaust gases that can almost completely burn and remove particulates accumulated on a wall portion by a regenerating process allowing residual ashes on the wall portion to easily move inside a through hole because the ashes are easily separated from the wall portion. In the honeycomb filter a columnar body made of porous ceramics, having parallel through holes in the length direction with a wall portion interposed therebetween, is designed so that part or all of the wall portion that separates the through holes from each other functions as a filter collecting particulates, wherein a length l of the longest side in a cross section perpendicular to the length direction of the through hole and a length L in the length direction of the columnar body satisfy: 60?L/l?500, and a surface roughness Ra (according to JIS B 0601) of the through hole inner wall satisfies: Ra?100 ?m.

Abstract: An object of the present invention is to provide a honeycomb structural body (filter) which has a low pressure loss upon collecting particulates, makes it possible to deposit a great amount of particulates and ashes, and is less likely to produce cracks.