PURPOSE: To provide the snow melting structure for the primary radiator of the reflector antenna in which the structure is simple and a sufficient snow melting effect is obtained with respect to the snow melting structure to prevent especially snow deposition onto an aperture of the primary radiator of a reflector antenna such as a parabolic antenna, a Cassegrain antenna, and a Glegory antenna used for the communication system utilizing a communication satellite.

CONSTITUTION: An enclosed space interrupted from atmospheric air is formed between both fedomes and a means 3 circulating hot air is provided in the enclosed space by covering an aperture at a tip of a primary radiator 2 in the reflector antenna comprising the primary radiator 2, a reflector 14 installed on a prolonged line of an axial line of the primary radiator and a main mirror finished surface installed opposite to the reflector with the two 1st and 2nd fedomes in duplicate.