| abstract |
A honeycomb structure includes a honeycomb structure body having a porous partition wall which cells and having a circumferential wall at an outer circumference thereof, and also includes a pair of electrodes on a side surface of the honeycomb structure body. An open frontal area of a center part is 0.70 to 0.95 times of that of an outer circumferential part, where the center part is defined as an area from a center of the honeycomb structure body to a position of 10% of a length from the center to the outer circumference in a direction toward the outer circumference in a cross-section orthogonal to the cells' extending direction, and the outer circumferential part is defined as an area from the outer circumference to a position of 10% of a length from the outer circumference to the center in a direction toward the center in the cross-section. |