Content server, the content transferring apparatus and the content playback device

The user registers the data of the new music CD to the content server device 10 (home of the PC), with a content transfer device 20 (mobile phone terminal), home and content reproduction apparatus 30 (car audio system) has been installed car during the alternate between, without any particular user to a special operation, the contents registered in the content server apparatus 10 is transferred to the content reproduction apparatus 30 by wireless LAN through the content transferring apparatus 20.