PURPOSE: To improve the reaction selectivily to H and Co by sticking an inorg. composite oxide consisting of rare earth metal or the like Al, oxygen on an inorg. oxide carrier having the surface consisting essentially of activated alumina and depositing a platinum group metal thereon.

CONSTITUTION: The perovskite type inorg. composite oxide expressed by the following formula ABX3 (A is one kind of metal selected among the group consisting of rare earth metals and titanium metals, B is Al, X is oxygen) is stuck on an inorg. oxide carrier of which at least the surface consists essentially of activated alumina, and at least one kind of platinum group metals is deposited thereon. The metal A in said inorg. compoiste oxide is contained preferably in a 0.1W10.0wt% range in terms of metal based on the weight of the carrier. The platinum group metal is deposited on the carrier at 0.1W1.0wt% rate in terms of metal and after calcination, the metal is reduced by a liquid phase reduction method and is dried, whereby the catalyst is prepd. The reaction selectivity of said catalyst to H and CO is improved stably and markedly, and the low temp. activity and durable performance thereof are improved as well.