1. An apparatus for monitoring a network in which a label switched path (LSP) can be set up, the network including a plurality of routers, comprising: a communication unit that communicates with a router among the plurality of routers; a collection unit that collects LSP path information via the communication unit, the LSP path information being maintained by the router; a storing unit that stores state information based on the LSP path information collected by the collection unit, the state information including information for identifying an LSP and information on a current path of the LSP; and a display unit that reads the state information for a selected LSP stored by the storing unit and graphically displays a path of the selected LSP, in accordance with a user's instruction.