Patent attributes
A honeycomb structure 20 is provided with multiple honeycomb units 10 having multiple through holes 12 arranged in parallel along the longitudinal direction, and a seal layer 26 for joining the units 10 via the outer faces 13 on which the through holes 12 are not opened. The honeycomb structure satisfies the expression 2≦A/B≦0.0002×C+5 (about 28000≦C), where A (g/cm3) represents a product of the apparent density of the honeycomb unit 10 and volume ratio of the honeycomb unit 10 to the whole honeycomb structure, B (g/cm3) represents a product of the apparent density of the seal layer 26 and volume ratio of the seal layer 26 to the whole honeycomb structure, and C (m2/L) represents a specific surface area per unit volume of the honeycomb structure 20.