To effectively suppress interference on other radio stations located in the vicinity, when the radio station performs radio communication with a registered radio station. A femto base station 1 stores a history of connection requests issued by an unregistered radio station that is not pre-registered in the femto base station 1. Then, the femto base station 1 determines the need of a adjustment of a radio resource used in communication with a registered radio station that is pre-registered in the femto base station 1 itself by using connection request frequencies each for one of unregistered radio stations obtained from the connection request history as an index.