The present invention provides a honeycomb structure in which a plurality of honeycomb segments each constituted by a cell structure having a plurality of cells divided from each other by partition walls and functioning as a passage for fluid and an outer wall provided at the circumference of the cell structure are bonded to each other at the outer walls by a bonding layer made of a bonding agent and converted into one piece, which honeycomb structure is characterized in that the bonding agent does not contain inorganic particles having diameters ( mu m) of at least 1.1 times the average surface roughness Ra ( mu m) of the outer wall, in an amount exceeding 30% by mass relative to the total of the bonding agent. In the honeycomb structure, the honeycomb segments as a constituent are strongly bonded to each other by a bonding agent and converted into one piece. <IMAGE>