PURPOSE: To reflect radio wave regardless of the rear rim of a predetermined body to make acquisition by radar difficult by a method wherein an electroconductive thin film layer, whose rear end rim with respect to the estimated comming direction of radar waves is formed so as to be oblique with respect to the direction of the radar wave, is bonded on the outer surfaces of the predetermined body.

CONSTITUTION: An electroconductive foil 3 is bonded on the surface of the main wing 2 of an aircraft 1. The rear end rim of the electroconductive foil 3 is cut and aligned with a different angle from the sweepback angle of the main wing 2. When radar wave 4 is projected from the front direction of the aircraft 1, an induced electric current 5, generated on the upper surface of the main wing 2, arrives at the rear end rim 8 of the electroconductive foil 8 before it arrives at the rear end rim 7 of the main wing and reflected radio wave 6 is formed by the discontinuous reduction of conductivity. The direction of the reflected radio wave 6 is the same as in the case, in which the plane configuration of the main wing 2 is only a part covered by the electroconductive foil 3. Accordingly, the reflecting direction of the radar wave 4 can be changed without changing any sweepback angle of the main wing 2. Accordingly, acquisition by radar can be made difficult without spoiling any characteristic of the main wing 2.