Abstract: The present invention provides a protector, especially a radiotherapeutic protector. The protector comprises a conductive baseplate with one side covered with an insulation layer and another side is mounted with a plentiful of antennae, and an electric connector is coupled on one end of the conductive baseplate. In one embodiment, the conductive baseplate is enveloped by the insulation layer, and the antennae penetrate through the insulation layer and connect to one side of the conductive baseplate. The protector of the present invention has the advantages of simplify in structure and low in price, and can effectively avoid the physical contact or collision between the radioactive source and the patient during treatment.