Exhaust purification device for an internal combustion engine

There is provided an exhaust purification device for an internal combustion engine, which is able to shorten a total time for forced regeneration of a DPF or the like, an exhaust passage (20) in communication with cylinders of the engine in connection, a NOx absorbent catalyst (22) for absorbing contained in the exhaust gas at the time of a lean operation of NOx and for releasing and reducing the absorbed NOx when a rich operation is performed, a filter (23) which is provided in the exhaust passage for collecting contained in the exhaust solids, a filter temperature rise detection means (40) for detecting the temperature of the filter and an exhaust gas cleaning control means (46) to switch an exhaust air / fuel ratio of the engine between the rich and lean at intervals of a short duration when the filter temperature rise detection means detects that the Filt ertemperatur reaches a predetermined temperature.