To provide a terminal for suppressing effect on an inner electronic circuit due to a radial power from the main antenna of a portable telephone terminal to the utmost by setting the main antenna at an open and close type plate part set at the lower part.

The main antenna of a portable telephone terminal is set at an open and close type plate 1 side made of materials whose radio trnasmissivity is satisfactory such as plastic which is set at the lower part of the portable telephone terminal. Then, the main antenna is obtained as a main antenna 2 for vertical polarization. Also, length A of the main antenna is set so as to be easily tuned with the use frequency bands of a variety of portable telephones.