A radar device comprising: multiple subarray antennas (1-1 to 1-N) each having multiple element antennas; multiple sum signal generation units (3-1 to 3-N) respectively connected to the multiple subarray antennas (1-1 to 1-N), for each generating a sum signal of signals of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has; multiple difference signal generation units (4-1 to 4-N) respectively connected to the multiple subarray antennas (1-1 to 1-N), for each generating a difference signal of the signals of the multiple element antennas (1-1 to 1-N) which each of the subarray antennas has (1-1 to 1-N); and an angle measurement unit (14; 53; 61) for performing a beamformer angle measurement on a target by searching for one or more angles of the target using the sum signals generated by the multiple sum signal generation units (3-1 to 3-N) and the difference signals generated by the multiple difference signal generation units (4-1 to 4-N); wherein the multiple sum signal generation units (3-1 to 3-N) generate the sum signals by combining the signals of the multiple element antennas in such a way that the signals of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has are in phase in a subarray beam direction, characterized in that the multiple difference signal generation units (4-1 to 4-N) each generate a first sum signal by dividing an aperture of each of the subarray antennas (1-1 to 1-N) into two parts, and combining signals of multiple element antennas for one of the two parts into which the aperture is divided, out of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has, in such a way that the signals of the multiple element antennas for the one of the two parts into which the aperture is divided are in phase in the subarray beam direction and also generate a second sum signal by combining signals of multiple element antennas for another one of the two parts into which the aperture is divided, out of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has, in such a way that the signals of the multiple element antennas for the other one of the two parts into which the aperture is divided are in phase in the subarray beam direction, and calculate a difference between the first sum signal and the second sum signal as the difference signal, wherein the subarray beam direction is changeable. multiple subarray antennas (1-1 to 1-N) each having multiple element antennas; multiple sum signal generation units (3-1 to 3-N) respectively connected to the multiple subarray antennas (1-1 to 1-N), for each generating a sum signal of signals of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has; multiple difference signal generation units (4-1 to 4-N) respectively connected to the multiple subarray antennas (1-1 to 1-N), for each generating a difference signal of the signals of the multiple element antennas (1-1 to 1-N) which each of the subarray antennas has (1-1 to 1-N); and an angle measurement unit (14; 53; 61) for performing a beamformer angle measurement on a target by searching for one or more angles of the target using the sum signals generated by the multiple sum signal generation units (3-1 to 3-N) and the difference signals generated by the multiple difference signal generation units (4-1 to 4-N); wherein the multiple sum signal generation units (3-1 to 3-N) generate the sum signals by combining the signals of the multiple element antennas in such a way that the signals of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has are in phase in a subarray beam direction, characterized in that the multiple difference signal generation units (4-1 to 4-N) each generate a first sum signal by dividing an aperture of each of the subarray antennas (1-1 to 1-N) into two parts, and combining signals of multiple element antennas for one of the two parts into which the aperture is divided, out of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has, in such a way that the signals of the multiple element antennas for the one of the two parts into which the aperture is divided are in phase in the subarray beam direction and also generate a second sum signal by combining signals of multiple element antennas for another one of the two parts into which the aperture is divided, out of the multiple element antennas which each of the subarray antennas (1-1 to 1-N) has, in such a way that the signals of the multiple element antennas for the other one of the two parts into which the aperture is divided are in phase in the subarray beam direction, and calculate a difference between the first sum signal and the second sum signal as the difference signal, wherein the subarray beam direction is changeable.