A honeycomb structure includes: a periphery-ground article obtained by grinding an outer peripheral portion of a cell structure 3 where honeycomb segments 11 are bonded by a bonding layer 12 at an outer wall 10 of each of them, and an outer peripheral coat layer 9 disposed on an outer peripheral face 8 of the periphery-ground article; wherein at least one of the bonding layer 12 and the outer peripheral coat layer 9 is formed using honeycomb-forming slurry containing biologically soluble fibers containing a metal oxide capable of extricating a metal ion and an inorganic binder containing a colloidal oxide having modified silica sol manufactured by adding a substance containing amine or an aqueous solution of a water-soluble metalate of an amphoteric metal to silica sol. Crack generation of the outer peripheral coat layer and/or deterioration of bonding strength of the bonding layer can be inhibited.