An exhaust emission control device for an internal combustion engine, which is capable of supplying a just enough amount of reducing agent to a NOx catalyst, thereby reducing exhaust emission and improving fuel economy. The device includes a three-way catalyst, a NOx catalyst provided downstream of the three-way catalyst, and an ECU. The ECU carries out rich spike control such that exhaust gases flowing into the NOx catalyst form a reducing atmosphere. During the control, the ECU calculates a reducing agent consumption amount of reducing agent in the exhaust gases consumed by the three-way catalyst, calculates a cumulative reducing agent amount as a total amount of reducing agent supplied to the NOx catalyst, depending on the reducing agent consumption amount, and terminates the control when the cumulative reducing agent amount becomes larger than a predetermined value.