To provide an exhaust-gas cleaning method facilitating contact of a catalyst metal and a PM to effectively oxidize and remove the PM.

Carbon powders contained in slurry are burnt out so that a three dimensional structure part 30 projecting from its surface into a pore 2 of a cell partition wall 12 is formed on a catalyst supporting layer 3. A surface-roughness of the catalyst supporting layer 3 is increased by the three dimensional structure part 30 so that the PM can easily be captured. Further, as the pore 2 is partitioned by the three dimensional structure part 30, the structure of a plurality of fine pores with the small pore diameter gathered together is formed, and the contact area of the captured PM and catalyst components is increased.