A device for purifying the exhaust gas of an internal combustion engine is disclosed. The device comprises a particulate filter (70) arranged in the exhaust system, which carry a catalyst for absorbing and reducing NO x . The catalyst absorbs NO x when the air-fuel ratio in the surrounding atmosphere thereof is lean and releases the absorbed NO x to purify NO x by reduction when the air-fuel ratio is the stoichiometric or rich. The device further comprises a catalytic apparatus (74) for purifying NO x arranged in the exhaust system upstream of the particulate filter, which has an oxidation function.