An objective of the present invention is to provide a method for producing a catalyst for exhaust gas removal having excellent heat tolerance and purification performance within a wide range of atmospheres and a catalyst obtained by the production method.The present invention relates to a method for supporting catalyst metal particles, comprising: (a) adding an iridium precursor and a palladium precursor to a solvent containing at least one member selected from the group consisting of polyvinylpyrrolidone, N-methylpyrrolidone, N-vinyl-2-pyrrolidone, and ethylene glycol; (b) adding a reducing agent to the obtained catalyst metal colloid; (c) obtaining a concentrated solution containing catalyst metal particles by subjecting the obtained solution to heat reflux; and (d) supporting the catalyst metal particles on a carrier, wherein the iridium content of the catalyst metal particles accounts for 3% to 10% by mass of the total mass of iridium and palladium.