Patent ID: 7641955

Claim:
A honeycomb structured body comprising: a pillar-shaped honeycomb block including a honeycomb unit in which a number of cells are longitudinally placed in parallel with a cell wall therebetween; and a sealing material provided on a peripheral portion of said pillar-shaped honeycomb block, wherein irregularities are formed on each peripheral face of said honeycomb structured body and said pillar-shaped honeycomb block, and said honeycomb unit comprises inorganic particles, as well as inorganic fibers and/or whiskers, and the inorganic fibers and/or whiskers increase a specific surface area of the honeycomb unit; when a least square curve is obtained by a least square method on the basis of points comprising the contour of a cross-section perpendicular to the longitudinal direction of said honeycomb structured body, a center-of-gravity of the least square curve is defined as c 1 , a distance between a minimum concentric circumscribed curve having c 1 as the center-of-gravity, derived from said least square curve and the center-of-gravity c 1 is defined as D 1 , a distance between a maximum concentric inscribed curve having c 1 as the center-of-gravity, derived from said least square curve and the center-of-gravity c 1 is defined as D 2 , and (D 1 −D 2 ) is defined as M 1 , the following inequality is satisfied: about 0.3 mm≦M 1 ; and when a least square curve is obtained by a least square method on the basis of points comprising the contour of a cross-section perpendicular to the longitudinal direction of said honeycomb block, a center-of-gravity of the least square curve is defined as c 2 , a distance between a minimum concentric circumscribed curve having c 2 as the center-of-gravity, derived from said least square curve and the center-of-gravity c 2 is defined as D 3 , a distance between a maximum concentric inscribed curve having c 2 as the center-of-gravity, derived from said least square curve and the center-of-gravity c 2 is defined as D 4 , and (D 3 −D 4 ) is defined as M 2 , the following inequality is satisfied: about 0.5 mm≦M 2 ≦about 7.0 mm.