An engine promoting DPF regeneration processing is provided. Catalyst activation processing and thereafter DPF regeneration processing are performed under control of a device. In the catalyst activation processing, a target temperature of exhaust at an exhaust exit of a catalyst is set to be in a first temperature region, and then the opening degree of an exhaust throttle device is controlled. In the DPF regeneration processing, the target temperature is set to be in a second temperature region. A target temperature of the exhaust at an exhaust inlet of a DPF is set to be in a third temperature region. The opening degree of the exhaust throttle device is controlled, and unburned fuel is supplied into the exhaust. The temperature regions are set to be successively higher, and a temperature difference between successive temperature regions is set to be successively lower.