Disclosed is a catalyst filter, which includes a catalyst support and a nano metallic catalyst sprayed to a surface of the catalyst support. The catalyst filter uses catalyst slurry prepared by using a particulate catalyst, in which a small amount of nano metallic catalyst exhibiting a catalyst performance is sprayed to a surface of the catalyst support, different from an existing patent technique in which catalyst particles are formed and prepared as a support to consume a large amount of catalyst. Therefore, the specific surface area of the catalyst filter is not smaller than the specific surface area of the nano catalyst particles, and thus the catalyst filter may effectively remove and decompose ultra-low concentration gas-state contaminants in an indoor air.