A radio base station according to an embodiment is a radio base station configured to use a specific frequency band which includes a plurality of component carriers having a predetermined bandwidth and which is allowed to be utilized by a plurality of network operators or a plurality of communication systems. The radio base station comprises: a controller configured to select, from among the plurality of component carriers, a target component carrier in which a reference signal used in the specific frequency band should be transmitted; and a transmitter configured to use the target component carrier to transmit the reference signal. The controller selects, as the target component carrier, a first component carrier that satisfies a first condition. The first condition is that an interference power amount falls below a predetermined threshold value.