An integration agent device and its fault management method for a node including multi-layered devices are disclosed to effectively control a node including two or more communication devices of different layers and integrally processing relevant fault information. The integration agent device includes: one or more control and management modules controlling and managing one or more communications network devices by layer; and an inter-layer interworking processing module integrating and processing information of the communications network devices by using inter-layer interworking information, and notifying a management system accordingly, wherein the information of the communications network devices is transmitted through the one or more control and management.