Abstract: Provided are an antenna beam directivity apparatus and an antenna beam directivity method by which directivity accuracy of the antenna beam can be improved without adding a large scale device. The antenna beam directivity apparatus, having an array power feeding system, is provided with: input signal vector generating means for generating an input signal vector based on an input signal; weight vector holding means for holding a weight vector; weight correcting means for correcting the weight vector based on a value of an inner product of the input signal vector and the weight vector, so that the value of the inner product becomes a first value for a reference signal; and beam forming means for forming a null beam in a direction of the reference signal.