To provide a network device management device allowing sure management of devices allocated on a network.

The network system 1000 is provided with PCs 101 and 102, devices 103 and 104, and a router 102 mounted between them. A discovery agent on the device 104 transmits a device starting message to a discovery proxy on the device 103. When receiving the device starting message, the discovery proxy on the device 103 accesses the device 104 based on address information to acquire device information of the device 104.