Abstract: A honeycomb structure includes a porous partition wall defining a plurality of cells, wherein the plurality of cells include a first cell and a second cell, on the partition wall disposed to surround the at least one first cell, a protrusion is each provided with, the first protrusion and the second protrusion are each disposed to at least partially overlap with each other on extended lines in extending directions of the respective protrusions, and an inter-protrusion length (X) of a distal end of the first protrusion and a distal end of the second protrusion is equal to or more than 10% and equal to or less than 70% with respect to a mutual distance (W) from the one part to the other part on the partition walls facing each other.

Abstract: A plugged honeycomb structure including: a pillar-shaped honeycomb structure body having porous partition walls made of a material including silicon carbide, and plugging portions, wherein a porosity of the partition walls is from 42 to 52%, a thickness of the partition walls is from 0.15 to 0.36 mm, a ratio of a volume of pores having pore diameters of 10 ?m or less to a total pore volume of the partition walls is 41% or less, a ratio of a volume of pores having pore diameters in a range of 18 to 36 ?m to the total pore volume is 10% or less, the pore diameter indicating a maximum value of the log differential pore volume is in a range of 10 to 16 ?m, and a half-value width of a peak including the maximum value of the log differential pore volume is 5 ?m or less.