Exhaust gas apparatus and method for purifiying exhaust gas in internal combustion engine

A diesel particulate filter 14 that traps particulate matters In an exhaust gas and a NOx trap catalyst 13 that traps NOx in the exhaust gas are disposed in art exhaust passage (10) in an internal combustion engine (1). When a regeneration timing of the diesel particulate filter (14)and one of a regeneration timing of SOx and a regeneration timing of NOx are overlapped, the diesel particulate filter regeneration is carried out first and thereafter, the SOx regeneration or the NOx regeneration is carried out. A diesel particulate filter 14 that traps particulate matters In an exhaust gas and a NOx trap catalyst 13 that traps NOx in the exhaust gas are disposed in art exhaust passage (10) in an internal combustion engine (1). When a regeneration timing of the diesel particulate filter (14)and one of a regeneration timing of SOx and a regeneration timing of NOx are overlapped, the diesel particulate filter regeneration is carried out first and thereafter, the SOx regeneration or the NOx regeneration is carried out.