A honeycomb structure includes porous partition walls via which a plurality of cells constituting through channels for a fluid are partitioned; and an outer peripheral wall positioned in the outermost periphery of the structure. Open frontal areas of predetermined cells in an end face of the structure on a fluid inlet side thereof and open frontal areas of remaining cells in an end face of the structure on a fluid outlet side thereof have plugged portions. The outward end faces of the plugged portions are flat, the plugged portions do not have any bubble having a diameter of 0.3 mm or more, and a value obtained by dividing the standard deviation of the plugging depths of the plugged portions by the average plugging depth of the plugged portions is 0.15 or less.