A control device and method for exhaust gas purification that can prevent the adsorption amount from becoming excessively lower than the saturated adsorption amount and can prevent the reduction efficiency of the reduction catalyst from degrading, including a device which can predict a transition of the temperature of the reduction catalyst and determine whether that temperature is decreasing; an apparatus which can control injection of the reducing agent according to a first amount that is smaller than a saturated amount corresponding to the temperature of the catalyst if it is determined that the temperature does not decrease continuously for a time; and a second apparatus which can control the injection of the reducing agent according to a second amount that is larger than the first amount and smaller than the saturated amount if it is determined that the temperature of the reduction catalyst continuously decreases for a time.