Even when terminals having different bandwidths require different amounts of BCH information, a radio base station apparatus in a scalable bandwidth system can transmit the BCH information required by the terminals. A base station (100) comprises a frame generating part (150) that generates a frame in which only common information directed to all of the terminals is placed in a band, which is assigned within a band having the largest one of the bandwidths supported by the base station (100) and has the smallest one of the supported bandwidths, and in which additional information different from the common information is placed in a band which is located within the band having the largest supported bandwidth and which is different from the band in which the common information is placed; and an RF transmitting part (180) that transmits the frame via a broad channel. In this way, even when terminals having different bandwidths require different amounts of BCH information, it is possible to transmit the BCH information requested by the respective terminals.