Patent ID: 7972677

Claim:
A honeycomb structure comprising: porous partition walls separating and forming a plurality of cells extending between two end faces, and an outer peripheral wall formed unitarily with the partition walls; wherein the cells include outermost peripheral portion partial cells each located in an outermost peripheral portion of the honeycomb structure and having an incomplete cell cross section, a part of which is brought into contact with the outer peripheral wall, and complete cells each having a complete cell cross section other than the outermost peripheral portion partial cells, the complete cells and the outermost peripheral portion partial cells having plugging material formed on one end portion in such a manner that an entire end face of the honeycomb structure shows a checkerwise plugging pattern, a length of the plugging material in the outermost peripheral partial cells is smaller than a length of the plugging material in the complete cells, some of the outermost peripheral portion partial cells are formed unitarily with the outer peripheral wall so as to be plugged over the entire length thereof, the length of the plugging material of each partial cell is based on a cell area ratio, and the cell area ratio is determined based on an equation in which the cell area ratio (%)=Area of outermost peripheral portion partial cell/Area of complete cell×100.