An array antenna device (100, 100A) including a plurality of patch antennas (10, 20, 40) arrayed in at least a polarization direction of the plurality of patch antennas, the array antenna device (100, 100A) comprising: a respective parallel line (31, 32) formed for each of the plurality of patch antennas in parallel to the polarization direction of the patch antenna, on the same plane as a patch element (11, 21) of the patch antenna, close to the patch element in a magnetic field direction of the patch antenna; and a bent line (33, 33A) configured to connect a first parallel line, which is formed close to a patch element of a respective first patch antenna, and to a second parallel line, which is formed close to a patch element of a respective second patch antenna, wherein the first patch antenna and the second patch antenna are arrayed so as to be adjacent to each other and the bent line (33, 33A) is shaped so as to be bent between the patch element of the respective first patch antenna and the patch element of the respective second patch antenna, wherein the respective parallel line and the bent line form a coupling line (30, 30A, 50, 60, 70), which is configured to couple part of an electromagnetic wave excited by the patch element to an adjacent patch antenna, wherein, in the coupling line, a gap between the respective parallel line and the patch element and a length of the bent line are set so that an electromagnetic wave coupled from one patch antenna to an adjacent patch antenna via space and an electromagnetic wave coupled from the one patch antenna to the adjacent patch antenna via the coupling line cancel each other, and wherein the plurality of patch antennas are arrayed into one of a quadrangular array, a triangular array, and an aperiodic array. the array antenna device (100, 100A) comprising: a respective parallel line (31, 32) formed for each of the plurality of patch antennas in parallel to the polarization direction of the patch antenna, on the same plane as a patch element (11, 21) of the patch antenna, close to the patch element in a magnetic field direction of the patch antenna; and a bent line (33, 33A) configured to connect a first parallel line, which is formed close to a patch element of a respective first patch antenna, and to a second parallel line, which is formed close to a patch element of a respective second patch antenna, wherein the first patch antenna and the second patch antenna are arrayed so as to be adjacent to each other and the bent line (33, 33A) is shaped so as to be bent between the patch element of the respective first patch antenna and the patch element of the respective second patch antenna, wherein the respective parallel line and the bent line form a coupling line (30, 30A, 50, 60, 70), which is configured to couple part of an electromagnetic wave excited by the patch element to an adjacent patch antenna, wherein, in the coupling line, a gap between the respective parallel line and the patch element and a length of the bent line are set so that an electromagnetic wave coupled from one patch antenna to an adjacent patch antenna via space and an electromagnetic wave coupled from the one patch antenna to the adjacent patch antenna via the coupling line cancel each other, a respective parallel line (31, 32) formed for each of the plurality of patch antennas in parallel to the polarization direction of the patch antenna, on the same plane as a patch element (11, 21) of the patch antenna, close to the patch element in a magnetic field direction of the patch antenna; and a bent line (33, 33A) configured to connect a first parallel line, which is formed close to a patch element of a respective first patch antenna, and to a second parallel line, which is formed close to a patch element of a respective second patch antenna, wherein the first patch antenna and the second patch antenna are arrayed so as to be adjacent to each other and the bent line (33, 33A) is shaped so as to be bent between the patch element of the respective first patch antenna and the patch element of the respective second patch antenna, wherein the respective parallel line and the bent line form a coupling line (30, 30A, 50, 60, 70), which is configured to couple part of an electromagnetic wave excited by the patch element to an adjacent patch antenna, wherein, in the coupling line, a gap between the respective parallel line and the patch element and a length of the bent line are set so that an electromagnetic wave coupled from one patch antenna to an adjacent patch antenna via space and an electromagnetic wave coupled from the one patch antenna to the adjacent patch antenna via the coupling line cancel each other, and wherein the plurality of patch antennas are arrayed into one of a quadrangular array, a triangular array, and an aperiodic array.