Exhaust gas purification catalyst

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Disclosed is an exhaust gas purifying catalyst, which comprises an oxygen absorbing material having a catalytic noble metal arranged at a lattice position or an interlattice position of a crystal structure of a composite oxide containing Ce and Zr, which is capable of sufficiently exhibiting a catalytic function even if a ZrO 2 mass ratio is out of the range of 20 to 30 mass% or 65 to 90 mass%. Specifically, in an exhaust gas purifying catalyst formed with a catalyst layer including a cerium-zirconium (CeZr) composite oxide, the composite oxide contains ceria (CeO 2 ) and zirconia (ZrO 2 ) in such a manner that a mass ratio of ceria to a total mass of ceria and zirconia falls within the range of 36 to 64 mass%. Further, the composite oxide contains, in the form of an oxide, a rare-earth metal other than cerium (Ce), in the range of 3 to 20 mass% with respect to a total mass of the composite oxide.