A radio base station monitoring method includes (A) a first radio base station detecting a second radio base station having newly detected a common control channel and a second radio base station having stopped detecting the common control channel as second radio base stations with a change, (B) the first radio base station notifying a network device of information about the second radio base stations with a change, and (C) the network device using information about second radio base stations associated with the first radio base station and the information about the second radio base stations with a change, which has been notified, to stop the operation of at least one of the first radio base station or the second radio base stations.