In multi-directional antennas connected to a digital TV broadcast signal receiver, when a receiving channel is selected, if an antenna is set to the same direction as a previously stored direction, and signals cannot be received, the previously stored direction data is deleted, and if the best receiving direction is searched by the auto-scan, and a receivable direction does not match the previously stored receiving direction, the stored direction information is all deleted, the entire area scan is performed over all directions for all channels, and a new receiving direction for each channel is determined by the obtained best receiving direction. By doing this, when signals becomes unreceivable on a given channel while receiving them with a direction-adjusted smart antenna, meaningless time for adjusting directions is saved and the best reception condition is always obtained quickly by detecting the direction misalignment as soon as possible and updating the direction data on all other channels as well in the early stages.