To provide an adaptive array antenna capable of increasing resolution of a variable beam direction of the antenna without increasing a calculation amount in arithmetic processing unit for optimally controlling a variable phase shifter. A parasitic element-equipped adaptive array antenna (100) includes n (n is an integer equal to or greater than 2) parasitic antenna elements (1011 to 101n), (n−1) fed antenna elements (1021 to 102n−1) which are coupled to the parasitic antenna elements (1011 to 101n) by electromagnetic fields, and (n−1) variable phase shifters (1041 to 104n−1) which change the phases of radio frequency signals to be supplied to the respective fed antenna elements (1021 to 102n−1). Each of the fed antenna elements (1021 to 102n−1) is arranged astride at least two of the parasitic antenna elements (1011 to 101n).