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 an end face of the structure on a fluid outlet side thereof are provided with plugged portions. Bubbles are formed in the plurality of plugged portions, and the center of each of the bubbles is positioned in a predetermined region of each of the plugged portions along the central axis direction thereof.