An exhaust gas purification apparatus that is disposed in an exhaust system of an internal combustion engine and that purifies an exhaust gas, the exhaust gas purification apparatus comprising: an exhaust gas purification catalyst that is disposed in the exhaust system and that has a catalyst layer formed on a substrate and including a support containing an OSC material having an oxygen storage capacity and a precious metal catalyst supported on this support; an upstream O 2 sensor that is disposed in the exhaust system upstream from the exhaust gas purification catalyst and that detects an upstream O 2 concentration, which is an oxygen concentration in the exhaust gas on the upstream side of the exhaust gas purification catalyst; a downstream O 2 sensor that is disposed in the exhaust system downstream from the exhaust gas purification catalyst and that detects a downstream O 2 concentration, which is an oxygen concentration in the exhaust gas on the downstream side of the exhaust gas purification catalyst; and a control section that is configured to be capable of executing main feedback control that calculates an air/fuel ratio for an air-fuel mixture being supplied to the internal combustion engine based on the upstream O 2 concentration and that sets a first control target value based on the calculated air/fuel ratio and a predetermined target air/fuel ratio, sub-feedback control that sets a second control target value by correcting the first control target value based on the downstream O 2 concentration, and air/fuel ratio adjustment control that adjusts the air/fuel ratio of the air-fuel mixture supplied to the internal combustion engine based on the second control target value, wherein the support in a prescribed region from a catalyst-outlet-side end at the downstream side of the exhaust gas purification catalyst contains an OSC material having a pyrochlore structure and an OSC material having an oxygen storage rate that is faster than that of the OSC material having a pyrochlore structure. an exhaust gas purification catalyst that is disposed in the exhaust system and that has a catalyst layer formed on a substrate and including a support containing an OSC material having an oxygen storage capacity and a precious metal catalyst supported on this support; an upstream O 2 sensor that is disposed in the exhaust system upstream from the exhaust gas purification catalyst and that detects an upstream O 2 concentration, which is an oxygen concentration in the exhaust gas on the upstream side of the exhaust gas purification catalyst; a downstream O 2 sensor that is disposed in the exhaust system downstream from the exhaust gas purification catalyst and that detects a downstream O 2 concentration, which is an oxygen concentration in the exhaust gas on the downstream side of the exhaust gas purification catalyst; and a control section that is configured to be capable of executing main feedback control that calculates an air/fuel ratio for an air-fuel mixture being supplied to the internal combustion engine based on the upstream O 2 concentration and that sets a first control target value based on the calculated air/fuel ratio and a predetermined target air/fuel ratio, sub-feedback control that sets a second control target value by correcting the first control target value based on the downstream O 2 concentration, and air/fuel ratio adjustment control that adjusts the air/fuel ratio of the air-fuel mixture supplied to the internal combustion engine based on the second control target value, wherein the support in a prescribed region from a catalyst-outlet-side end at the downstream side of the exhaust gas purification catalyst contains an OSC material having a pyrochlore structure and an OSC material having an oxygen storage rate that is faster than that of the OSC material having a pyrochlore structure.