PROBLEM TO BE SOLVED: To provide an exhaust emission control device for a urea SCR system, for enabling an injector to be more effectively cooled.SOLUTION: The exhaust emission control device is provided for the selective catalyst reduction system using urea as reagent. The exhaust emission control device includes a tank storing urea water, the injector having a solenoid for controlling the opening of a solenoid valve, for, when energized through the solenoid, supplying the urea water into an exhaust gas flow while cyclically repeating injection to be on/off, a pump for supplying the urea water from the tank into the injector, and a control unit for controlling the injection of the urea water. The control unitt has a normal mode and a cooling mode as control modes. The control unit controls the injector so that a time for the injection to be on is shorter in the cooling mode than in the normal mode.SELECTED DRAWING: Figure 1
