PURPOSE: To facilitate the tracking test of a radar antenna angle, by moving a target horn corresponding to the difference of a set angle and the antenna angle to automate the movement of the target horn.

CONSTITUTION: The signal corresponding to the angle between the target horn preset in an angle setting apparatus 6 and a radar apparatus and the signal proportional to the antenna angle due to a signal antenna 3 and a signal treating apparatus 4 are compared by an angle error detecting apparatus 7. In this case, a drive apparatus 8 responds to the error signal outputted from the apparatus 7 to automatically control the movement of the horn 1 which is, in turn, automatically moved to an accurate angle position only by setting a desired angle and the tracking test of a radar antenna angle can be easily performed.