A ceramic honeycomb structure that excels in not only the performance of removing hazardous gases, such as HC and NOx, emitted from internal combustion engines but also catalytic reactivity. There isprovided a ceramic honeycomb structure consisting of one or a combination of two or more porous ceramic members of columnar honeycomb structure having a multiplicity of through holes arranged in parallel with a partition wall interposed therebetween, wherein the partition wall is constituted of a sintered material of such a pore structure that on a pore diameter distribution curve, providing thatpores of 0.05 to 150 m diameter are referred to as the first pore group while pores of 0.006 to 0.01 m diameter are referred to as the second pore group, each of the region of first pore group and the region of second pore group has one or more pore distribution peaks (maximum values).