An antenna package having a cavity structure comprising: an antenna substrate having a plurality of radiation patches formed on an upper surface thereof, and a plurality of signal processing elements formed on a lower surface thereof; and a cavity substrate is formed with a plurality of accommodation portions accommodating each of the plurality of signal processing elements, and disposed on the lower surface of the antenna substrate, wherein the antenna substrate comprises, a plate-shaped ceramic substrate; a first RF signal transmission pattern which is formed on the ceramic substrate; a first RF signal distributor which is formed on the ceramic substrate, and has an input terminal connected to one end of the first RF signal transmission pattern and a plurality of output terminals connected to some of the plurality of signal processing elements, and a second RF signal distributor which is formed on the ceramic substrate to be spaced apart from the first RF signal distributor, and has an input terminal connected to the other end of the first RF signal transmission pattern and a plurality of output terminals connected to the plurality of signal processing elements other than some of the plurality of signal processing elements, wherein the cavity substrate comprises; a cavity frame that has a lattice shape and in which the plurality of accommodation portions are disposed in a matrix; and a second RF signal transmission pattern which is formed on a lower surface of the cavity frame, and wherein one end of the second RF signal transmission pattern is connected to an RF signal transmission electrode, and the other end of the second RF signal transmission pattern is formed to extend toward the center of the cavity frame and is connected to the first RF signal transmission pattern of the antenna substrate through a via hole, to form a T junction distributor. an antenna substrate having a plurality of radiation patches formed on an upper surface thereof, and a plurality of signal processing elements formed on a lower surface thereof; and a cavity substrate is formed with a plurality of accommodation portions accommodating each of the plurality of signal processing elements, and disposed on the lower surface of the antenna substrate, wherein the antenna substrate comprises, a plate-shaped ceramic substrate; a first RF signal transmission pattern which is formed on the ceramic substrate; a first RF signal distributor which is formed on the ceramic substrate, and has an input terminal connected to one end of the first RF signal transmission pattern and a plurality of output terminals connected to some of the plurality of signal processing elements, and a second RF signal distributor which is formed on the ceramic substrate to be spaced apart from the first RF signal distributor, and has an input terminal connected to the other end of the first RF signal transmission pattern and a plurality of output terminals connected to the plurality of signal processing elements other than some of the plurality of signal processing elements, wherein the cavity substrate comprises; a cavity frame that has a lattice shape and in which the plurality of accommodation portions are disposed in a matrix; and a second RF signal transmission pattern which is formed on a lower surface of the cavity frame, and wherein one end of the second RF signal transmission pattern is connected to an RF signal transmission electrode, and the other end of the second RF signal transmission pattern is formed to extend toward the center of the cavity frame and is connected to the first RF signal transmission pattern of the antenna substrate through a via hole, to form a T junction distributor.