Exhaust gas purification catalyst

An exhaust gas purifying catalyst comprising a first catalyst layer including a first section and a second section in an exhaust gas flow direction, the first section being located on an upstream side in the exhaust gas flow direction relative to the second section,

• wherein the first section and the second section of the first catalyst layer each contains a catalytically active component including a specific element,
• a concentration of the specific element in the first catalyst layer is higher in the first section than in the second section, in terms of mass per unit volume,
• a ratio of a1 to a2, a1/a2, is 1.1 or more, where a1 represents a mass of the specific element that is present on a surface side of the first section of the first catalyst layer when the first section is divided in half along a thickness direction of the first catalyst layer, and a2 represents a mass of the specific element that is present on another side than the surface side of the first section of the first catalyst layer, and
• a ratio of b1 to b2, b1/b2, is 0.9 or more and 1.03 or less, where b1 represents a mass of the specific element that is present on a surface side of the second section of the first catalyst layer when the second section is divided in half along a thickness direction of the first catalyst layer, and b2 represents a mass of the specific element that is present on another side than the surface side of the second section of the first catalyst layer.