A honeycomb structure is provided not to be injured and put in parallel by settling a space maintainer, to have a small thickness deviation of a glue layer and to generate no crack to the glue layer or a sealant layer in a regenerative process. A honeycomb structure comprises ceramic block and a sealant layer. The ceramic block comprises a plurality of honey-comb plastic objects(110), a glue layer(101) and a space maintainer(10). The honey-comb plastic object has a pillar shape which is in parallel formed to a longitudinal direction. The glue layer sticks an interval of a side of the honey-comb plastic object. The space maintainer is arranged between the sides of the honey-comb plastic object. The sealant layer is formed in an outer circumference of the ceramic block. The space maintainer is made of the incombustible material.