Honeycomb structured body

The present invention provides a honeycomb structured body capable of achieving more effective use of a catalyst in partition walls and having excellent exhaust gas conversion performance. The present invention relates to a honeycomb structured body including: a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, wherein the honeycomb fired body contains ceria-zirconia composite oxide particles and alumina particles, the partition wall of the honeycomb fired body contains macropores having a pore size of 2 to 50 μm, and in an electron microscope image of a cross section of the partition wall, the percentage of the area occupied by pores having a pore size of 5 to 15 μm is at least 85% of the total area of the macropores.