To provide an antenna directivity trimming method and an antenna which solves the directivity deviation depending on the frequency.

According to the method of trimming the reflectivity of an antenna comprising three or more vertically stacked antenna element blocks 5 each composed of a plurality of antenna elements 3, the uppermost or lowermost antenna element block 5 is set to a feed phase of 180° or -180° to other antenna block 5, so that the feeding direction of each antenna element 3 in the uppermost or lowermost antenna element block 5 is reverse to that of each antenna element 3 in other antenna block 5. Since the phase difference resulting from the reversing of the feeding direction does not depend on the frequency, the directivity deviation depending on the frequency is small.