To provide a composite machine for effectively utilizing an existing key to thereby attain the remote control of a camera function.

A mobile phone 1 has a twofold structure comprising a lid 2 and a main body 3, and a key unit 4 is removably fitted to the main body 3. When the key unit 4 is fitted to the main body 3 and a camera mode is not set, the mobile phone 1 acts like an ordinary mobile phone. When a camera key 404 is operated and the mode is shifted to the camera mode, it is possible to remove the key unit 4 from the main body 3 and to carry out photographing. That is, zoom processing is performed by operating a mail key 405 or an address key 408. The operation of a cross key 406 controls the direction of an imaging lens unit 118 in accordance with its operating direction. When the operation of a determination key 407 is detected, image data are subjected to compression processing and the compressed data are stored into an image memory.