The present invention relates to a transmission power control apparatus and a radio base station that properly maintain a target value of uplink transmission quality as a reference for transmission power control. An object of the present invention is to accurately maintain a target value at a proper value at low cost. Thus, a transmission power control apparatus according to the present invention includes a monitor section which monitors a value of the uplink transmission quality; and a target value update section which updates the target value in such a manner as to decrease a difference between the value of the transmission quality monitored and the target value when the transmission quality is not in a predetermined range which includes the target value of the transmission quality as a reference.