Patent ID: 8470254

Claim:
A honeycomb filter comprising a honeycomb-structured substrate provided with a plurality of cells separated by partition walls of porous ceramic having pores and functioning as exhaust gas passages, the honeycomb-structured substrate having an exhaust gas inflow side and an exhaust gas outflow side, wherein plugging portions are formed alternately in one side open end portions and the other side open end portions of the plural cells, at least in open pores formed by the particles constituting the partition walls and/or gaps between the particles, a composite region is formed by depositing particles having an average particle diameter smaller than that of the particles in a surface layer portion of the partition walls on the exhaust gas inflow side, the partition walls have an average pore diameter of 5 to 40 μm and a porosity of 35 to 75%, the particles deposited have an average particle diameter of 1 to 15 μm, and the composite region has a height of 80 μm or less with respect to the partition wall surface direction from the outermost contour line of the partition walls.