PURPOSE: To increase a beam width reflected in a reflecting mirror and to facilitate the adjustment of the direction of the parabolic antenna by providing detachably an antenna cover made of a radio wave absorbing material to a circumference part of a reflecting mirror of the parabolic antenna.

CONSTITUTION: The parabolic antenna is provided with a parabolic reflecting mirror 1 receiving an incoming radio wave and reflecting a sharp beam, a primary radiator 2 receiving a radio wave reflected in the reflecting mirror 1, and a frequency converter 3 fitted to the primary radiator 2 and converting an inputted radio wave into an intermediate frequency signal, and an antenna cover 4 made of a radio wave absorbing material as a major material is provided removably to the circumference of the reflecting mirror 1. The substantial aperture diameter of the reflecting mirror 1 is reduced by providing the antenna cover in this way to increase the beam width and the projection the beam to the primary radiator 2 is facilitated to easily adjust the direction of the antenna.