To reduce the size and weight of a phased array antenna.

Transmission/reception modules 81-8N are connected to a power supply circuit 3 to distribute the radar transmission frequency signal from a transmission excitation unit 1 in the direction of the angle of elevation in a corresponding manner, and slot antennas 91-9N are connected to each of the corresponding transmission/reception modules 81-8N. The continuously arranged slot antennas 91-9N form a surface array by arranging the slots in the direction of the azimuth angle, and the transmission/reception modules 81-8N are arrayed only in the direction of the angle of elevation (in the longitudinal direction). The number of modules is considerably reduced, and the size and weight of the antennas and the radar can be reduced.