A honeycomb structure includes a honeycomb substrate having a porous partition wall that defines a plurality of cells that extend from an inlet end face as an inlet side for a fluid to an outlet end face as an outlet side for the fluid, and a porous circumferential wall that is monolithically formed with the partition wall, and a coat layer that is disposed on at least a part of the outer surface of the circumferential wall. Here, a part of the coat layer penetrates into the pores of the circumferential wall, and a thickness of the part of the coat layer that penetrates into the pores of the circumferential wall is from 1 to 90% of the thickness of the circumferential wall.