A booster capable of preventing itself from adversely influencing a base station. This booster comprises a plurality of downstream signal amplifying parts (111-1 to 111-4) and a plurality of upstream signal amplifying parts (112-1 to 112-4). A received signal analyzing part (116) analyzes the perch channel information of a signal received from a base station to generate analysis information. When the analysis information shows that the reception quality of the received signal is below a threshold value, halt control parts (118,124) halts the operations of those ones of the downstream signal amplifying parts (111-1 to 111-4) and upstream signal amplifying parts (112-1 to 112-4) that are related to that analysis information. When the analysis information shows that a path-loss value or a base station interference power is above a threshold value, the halt control parts (118,124) may halt the operations of those ones of the downstream signal amplifying parts (111-1 to 111-4) and upstream signal amplifying parts (112-1 to 112-4) that are related to that analysis information.