A carbon monoxide removing catalyst whose catalytic activity is higher than conventional carbon-monoxide-methanation-reaction catalyst comprising an oxide support containing an oxide containing Co and Zr, and a Ru, Pt, Rh and/or Pd noble metal catalyst loaded on the oxide support, capable of removing carbon monoxide by means of carbon monoxide methanation reaction. The carbon monoxide removing catalyst has higher catalytic activity with respect to carbon monoxide methanation at low temperatures, compared with carbon monoxide removing catalysts which use oxides of Zr--Fe, Zr--Mn, and the like, or zirconia, as the support. A number-of-atom ratio of Co/Zr can be 1/3 or more and 3/1 or less.