In a drone-type radio relay apparatus, it is provided of an antenna system capable of suppressing an inclination of an antenna due to a strong wind during a stationary flight (hovering). The antenna system is provided with a long-shaped antenna 110 connected to a relay station via a cable, and an antenna guide mechanism that is fixed to a body of a drone and guides the antenna so as to be movable in an up-down direction of a basic attitude of the drone.