In a honeycomb structure 1 which is made of a ceramic and in which a plurality of honeycomb segments 12 having cell structures 5 and porous outer walls 7 on outer peripheries of the cell structures 5 are integrated by bonding these outer walls 7 to one another with a bonding material 8, each of the cell structures being provided with a plurality of cells 3 constituting fluid channels divided by porous partition walls 2, a base material constituting the honeycomb structure 1 has a thermal conductivity of 0.1 to 20 W/mK. Moreover, an outer periphery coating material constituting the outer peripheral wall of the honeycomb structure 1 has a porosity of 10 to 60%. Furthermore, the outer periphery coating material constituting the outer peripheral wall of the honeycomb structure 1 has a thermal conductivity of 0.01 to 0.5 W/mK.