PURPOSE: To attain automatic tracking through the use of other frequency channel even when a frequency channel having been used for the automatic tracking of a broadcast satellite is faulty.

CONSTITUTION: A receiver 4 outputs a reception strength of a radio wave in a frequency channel set by a frequency changeover device 5 to a tracking state evaluation device 6 and an antenna control panel 7. The antenna control panel 7 gives an antenna drive command to motors 2, 3 based on the reception strength to allow an antenna 1 to trace a broadcast satellite automatically. The tracking state evaluation device 6 decides whether or not the automatic tracking of the broadcast satellite is normally implemented based on the reception strength and also evaluates the state of the automatic tracking. When the tracking state evaluation device 6 decides it that the automatic tracking is not normally implemented, the antenna control panel 7 uses sequentially radio waves of all receptible frequency channels to implement the automatic tracking of the broadcast satellite and then uses the radio wave of the frequency channel having the best evaluation result by the tracking state evaluation device 6 to implement the automatic tracking of the broadcast satellite.