A portable communication machine includes RF data generating means, RF wireless transmitting means for transmitting transmission data as an RF signal, RF wireless receiving means for receiving an RF signal transmitted from a vehicle-mounted machine, RF data analyzing means for analyzing received data, key operating means for instructing to control a vehicle by a user, storing means for storing control data of a vehicle-mounted information apparatus, attachable/detachable external apparatus communicating means, and controlling means for controlling the RF data generating means, the RF data analyzing means, the key operating means and the external apparatus communicating means, and is used along with an external apparatus and the vehicle-mounted information apparatus.