A honeycomb structure includes a pillar-shaped honeycomb structure body having a porous partition wall defining a plurality of cells serving as fluid through channels extending from a first end face to a second end face, and having a circumferential wall disposed so as to encompass the circumference of the partition wall, wherein a thickness of the partition wall is 50 to 132 μm, a porosity of the partition wall is 40 to 55%, an open frontal area of pores on the surface of the partition wall per unit surface area of the partition wall is 10 to 15%, and a percentage (S0˜10/Sall×100%) of the ratio of an opening area S0˜10 of the pores having an opening diameter of 10 μm or less to a total opening area Sall of the pores opened to the surface of the partition wall is 90% or more.