PURPOSE: To provide a jamming wave directing device capable of always directing jamming wave to a target even if the distance between an airplane and the target or the attitude angle of the airplane is varied.

CONSTITUTION: When an airplane starts light, information on self-position, the attitude angle of the airplane, and a target position is send to a processor 11 from a controller 15. The processor 11 instructs a transmitter 12 to send a jamming electric wave and calculates the directing angle to the target of an electric wave directing device 14 based on the information on the self- position, the attitude angle of the airplane, and the target position sent from the controller 15 and outputs the calculated data to the electric wave directing device 14. The electric wave directing device 14 directs the jamming wave toward the target according to the angle information given by the processor 11.