A network management apparatus and method for remotely controlling a state of an IT device in order to use WOL to change a remote device from an inactive state to an active state over an IP network. The network management apparatus includes a detection pattern generator, a remote state controller, and a wake-up cause analyzer. By activating an inactivated PC connected over an IP network and positioned at a remote site using WOL to control a state of another IT device interoperating through the IP network as well as a state of the PC, it is possible to inactivate the device without unnecessarily having to leave the device on and then control the device as necessary, thereby reducing power consumption of the device and extending a lifetime of the device.