Provided are a radio base station and a method of receiving a physical control channel which are capable of achieving enhanced data-transmission efficiency of an uplink physical channel when a code division multiple access scheme is used. The radio base station includes: a correlation unit configured to determine a degree of correlation between a code word transmitted from the mobile device through a physical control channel and each replica of the code word, and to then select the replica having a higher degree of correlation than a predetermined degree; an identification unit configured to identify a control information piece contained in the selected replica; and a code-word replica generator configured to reduce the number of the replicas when the control information piece is identified.