Patent attributes
Provided are a hollow inner electrode constituted by an electrically conductive filter capable of capturing particulates, a cylindrical outer electrode circumferentially surrounding the electrode, a housing incorporated in a flow passage of exhaust and accommodating the electrodes and, a temperature sensor for detecting temperature of the exhaust and an electric discharge controller for controlling electric power to be distributed to the electrodes and on the basis of a detected value of the temperature sensor. When the temperature of the exhaust obtained by the temperature sensor is lowered, electric power necessary for generation of discharge plasma is distributed by the discharge controller to the electrodes and, thereby oxidizing the particulates captured by the electrode to reduce electricity consumption.