When using a plurality of antenna elements, calibration is performed appropriately, while preventing processing time from increasing. A base station apparatus has a plurality of antenna elements; a combiner configured to receive and combine downlink transmission signals, each including a reference signal, from monitor ports provided corresponding to the antenna elements; a channel estimator configured to estimate a channel of the reference signal for each of the antenna elements; and a calibration controller configured to calculate a calibration correction value to be applied to each of the antenna elements based upon channel estimation result.