Exhaust emission control device

An exhaust emission control device has operating condition detecting means (66) for detecting an operating condition of an engine, fuel control means (64) for controlling fuel supply into a combustion chamber of the engine on the basis of an output of the operating condition detecting means, a turbo charger (40) for supercharging a suction air with an exhaust gas of the engine, wherein a filter (51) for capturing particulates in the exhaust gas is disposed in an exhaust gas passage on the downstream side of a turbine (421) of the turbo charger (40), and the filter holds alkaline metal catalyst. Exhaust gas temperature sensing means (55) senses (or estimates) the exhaust gas temperature near the filter, and supercharging pressure control means (62) controls a supercharging pressure of the turbo charger to be increased when the exhaust gas temperature exceeds a predetermined temperature.