A high heat-resistive catalyser formed as a catalyst including a composite particle composed of a noble metal particle and a co-catalytic metal compound particle contacting, as a metal or as an oxide, with the noble metal particle, and a substrate carrying the noble metal particle and the co-catalytic metal compound particle, is produced by having a noble metal salt aqueous solution and a co-catalytic metal salt aqueous solution concurrently provided in a reverse micelle preparing reverse micellar solution containing a noble metal precursor and a co-catalytic metal precursor, and having a substrate carrying a composite particle comprising the noble metal precursor and the co-catalytic metal precursor concurrently reduced as a noble metal particle and a co-catalytic metal particle, respectively.