A network management system that is capable of managing each device in an information processing device efficiently even though on a network there are a plurality of the information processing apparatuses which search for devices to manage. A network management system comprises a multi-function printer (MFP) connected to a network, and a network management station that searches and manages the MFP. The MFP comprises a search source information recording unit that records information related to the network management station, which is a transmitter of a search packet, as search source information in response to receipt of the search packet, and a search source information transmitting unit that transmits the search source information to the network management station in response to request from the network management station. The network management station comprises a search source information acquisition requesting unit that requests acquisition of the search source information to the device, and a search source information obtaining unit that obtains the search source information transmitted from the MFP.