There is provided a honeycomb structured body having improved durability in a honeycomb structure body obtained by unitarily bonding a plurality of honeycomb segments. There is provided a honeycomb structure body 1 including a plurality of honeycomb segments 12 each having an outer wall 7, partition walls 2 disposed in the outer wall 7, and a plurality of cells 3 separated from each other by the partition walls 2 and extending in an axial direction, a bonding layer 8 interposed between the plurality of honeycomb segments 12 to unitarily bond the honeycomb segments 12, and an intermediate layer 9 interposed between the bonding layer 8 and the honeycomb segments 9. In the honeycomb structure body 1, pores having a diameter of 0.5 .mu.m or more of the intermediate layer 9 occupies 25% by volume or less of the whole volume of the intermediate layer 9.