A mounting pole 2a is independently installed in a place such as a park or a road where the beauty of the environment is an important factor. The mounting pole 2a has a communication mounting part 9a on the top thereof. A communication device 1a for outdoor use has an antenna 3a directly fixed on the top thereof and removably fitted in a groove of the device mounting part 9a. The device 1a has a connector 7a and no wiring thereof is exposed to the outside. The device la is electrically connected with the outside device through the connector 7a. In the mounting part 9a of the mounting pole 2a, there is provided a connector 8a at a position suitable for connection with the connector 7a in fitting engagement relationship. Wirings 10a interconnecting the connector 8a and the outside device are all laid through the interior of the mounting pole 2a. Consequently, none of the wirings 10a is exposed to the outside.