A honeycomb structured body includes a plurality of honeycomb members which are bonded to one another by interposing an adhesive layer. Each of the honeycomb members has a number of cells placed in parallel with one another in the longitudinal direction with a cell wall therebetween. When the longitudinal direction is defined as the orientation axis, the degree of orientation .OMEGA. of the inorganic fibers in the adhesive layer obtained by the Saltykov method is set in the range of about 0.2.ltoreq..OMEGA..ltoreq.about 0.7 or in the range of about -0.7.ltoreq..OMEGA..ltoreq.about -0.2 in the adhesive layer.