The present invention provides a catalyst module for removing harmful gas, wherein an oxidation reaction or reduction reaction of harmful gas is carried out in a self-heating heating carrier. According to an embodiment of the present invention, the catalyst module for removing harmful gas comprises: a heating carrier composed of an electrically heatable heating body, including one or more flow channels inside, and having a porous structure with pores; and a catalyst region formed on at least a portion of the surface of the heating carrier including the flow channels and containing a catalyst material for promoting a decomposition reaction of harmful gas passing through the flow channels, wherein the catalyst region comprises: a first catalyst layer having a first catalyst material loading amount in the pores of the heating carrier; and a second catalyst layer applied on the inner surface of the heating carrier.