A honeycomb structure includes porous partition walls defining cells which extend from a first end face to a second end face and which become through channels for a fluid, and a porous circumferential wall integrally formed with the partition walls to surround an outermost circumference of the partition walls, a thickness of the partition walls is from 101 to 381 μm, porosities of the partition walls and the circumferential wall are both 48% or more, a porosity in a surface of the circumferential wall is higher than a porosity of an inner surface of the circumferential wall, and an average pore diameter in the surface of the circumferential wall is 10 μm or more.