To prevent the head part from being kept radiated with a large amount of microwaves when an antenna is used for a long time by providing a radio wave absorbing material or a radio wave reflecting material in a shape so as to cover the antenna between the antenna and the head part of a user.

This cover 3 composed of the radio wave absorbing material formed by mixing the powder of carbon, ferrite and a magnetic material into synthetic rubber and synthetic resin is mounted between the antenna 2 of a portable telephone main body 1 and the head part of the user by an attaching tool 4 in the shape for covering the antenna 2. It is in a structure capable of being housed on the front surface, on the back surface or in the inside of the portable telephone main body when it is not used. Radio waves are radiated from the antenna 2 towards all directions, however, since the radio waves radiated towards the head part of the user are absorbed by the cover 3, they are substantially attenuated. Also, the cover by the radio wave absorbing material in a semi-cylindrical shape whose base material is the synthetic rubber and the synthetic rubber in the semi-cylindrical shape not provided with the radio wave absorbing material can be adhered or welded, formed into a cylindrical shape, put on the antenna and integrated.