It is an assignment to provide a carbon monoxide removing catalyst whose catalytic activity is higher than conventional carbon-monoxide-methanation-reaction catalyst. It is characterized in that it comprises an oxide support composed of an oxide containing Co and Zr, and a noble metal catalyst selected from the group consisting of Ru, Pt, Rh and Pd, and loaded on the oxide support, and it can remove carbon monoxide by means of carbon monoxide methanation reaction. A carbon monoxide removing catalyst of the present invention is such that such an effect is available that the catalytic activity with respect to carbon monoxide methanation reaction is higher when being low temperatures, compared with carbon monoxide removing catalysts which use oxides of Zr—Fe, Zr—Mn, and the like, or zirconia, as the support. In particular, it is desirable that a number-of-atom ratio of Co/Zr can be 1/3 or more and 3/1 or less.