A vertical axis driver drives a vertical axis for azimuth angle tracking. A horizontal axis driver drives a horizontal axis for elevation angle tracking. A cross horizontal axis driver drives a cross horizontal axis to which an antenna is attached, that is rotatable around an axis orthogonal to the horizontal axis. An arithmetic processing controller generates a drive signal of a constant azimuth angle the vertical axis when a maximum elevation angle of the antenna is greater than or equal to a set angle in a path of the target object in a single time of continuous tracking. When the maximum elevation angle of the antenna is less than the set angle in the path of the target object in the single time of continuous tracking, the controller issues a drive command of an azimuth angle direction to the vertical axis.