Honeycomb structure

A honeycomb structure comprising:

• a pillar-shaped honeycomb structure body that includes a porous partition wall arranged to surround a plurality of cells that acts as fluid through channels extending from a first end face to a second end face, wherein
• when a thickness (μm) of the partition wall is defined as T1 and, among pores formed in the partition wall, a value of an average pore diameter (μm) of specific pores whose pore diameters measured by a mercury press-in method are 20 to 100 μm is defined as D(20 to 100),
• T1/D(20 to 100) that is a value obtained by dividing the T1 by the D(20 to 100) is not less than 2.4,
• a ratio of a pore volume of the specific pores to an overall pore volume of the partition wall is 5 to 45%, and
• a ratio of a pore volume of large pores whose pore diameters is not less than 100 μm to the overall pore volume of the partition wall is not more than 5%.