PROBLEM TO BE SOLVED: To suitably oxidize and remove hydrogen sulfide discharged in the case of regeneration from sulfur poisoning of an exhaust gas purification means such as a NO x catalyst. SOLUTION: An exhaust emission control device of an internal combustion engine comprises an exhaust gas purification means 20 which is placed in an exhaust passage 15 of the internal combustion engine 10 in order to purify exhaust gas discharged from a combustion chamber 13, and an oxidizing-gas supply means 40, 41 for supplying oxidizing gas to the exhaust passage 15 in the position downstream of the exhaust gas purification means 20. Since the oxidizing gas is supplied to the position downstream of the exhaust gas purification means 20, the hydrogen sulfide discharged in the case of regeneration from sulfur poisoning of the exhaust gas purification means 20 can be oxidized and removed. Further, SO x formed after decomposition of the hydrogen sulfide is not reabsorbed to the exhaust gas purification means 20. Consequently sulfate-removing efficiency is increased in the case of regeneration from the sulfur poisoning. COPYRIGHT: (C)2007,JPO&INPIT