The invention relates to a device and a method for purifying exhaust gases for an internal combustion engine, with a multi-flow exhaust gas system having, at least in individual regions, several partial exhaust gas lines, and in which a NOx storage catalytic converter device and a SCR catalytic converter device are located. According to the invention, the NOx storage catalytic converter device (7) and the SCR catalytic converter device (9) are arranged distributed on different partial exhaust gas lines (6, 8) such that for a nitrogen oxide-Filled nitrogen oxide store of the NOx storage catalytic converter device (7) for a specified time interval a defined amount of the exhaust gas flow (16) produced by substoichiometric rich operation of the internal combustion engine (2) for production of a reducing agent, in particular for producing ammonia, flows via the NOx storage catalytic converter device (7) to the SCR catalytic converter device (9), in which the produced reducing agent, in particular ammonia, can be stored.