There is disclosed a honeycomb structure onto which a large amount of catalyst can be carried while suppressing an increase in pressure drop. In a honeycomb structure comprising porous partition walls by which a plurality of cells that become through channels of a fluid are partitioned and in which a plurality of pores are formed. In each of the partition walls, pores having pore diameters larger than a thickness of the partition wall in a section thereof which is perpendicular to an extending direction of the cells are formed so as to occupy 4 to 11% of the total volume of the pores formed in the partition walls.