The present invention relates to an antenna apparatus and, in particular, comprises: a main housing having an inner space formed therein so as to embed a main board and having a plurality of radiating fins provided on an outer surface thereof; a cover housing provided so as to shield the inner space of the main housing and having a plurality of radiating fins provided on an outer surface thereof; and a plurality of unit antenna blocks detachably coupled so as to occupy a portion of the outer surface of the cover housing, and having an antenna substrate embedded therein, the antenna substrate having one or more antenna elements and one or more antenna filters combined thereto, wherein the plurality of unit antenna blocks are signal-connected to the main board via at least one connecting card, thereby providing an advantage that dual banding can be realized as well as enabling effective heat dissipation.