To use the remote commander by other device by adding a function that receives information from the device main body to the remote commander so as to down-load data set by the remote commander.

When a data reception button R of a remote commander COM is depressed, a command of a data transmission request is generated and a main body CNV of a car navigation system stops an operation of a conventional car navigation to enter data transmission and continues the data transmission till all data set to the CNV are sent out. When the remote commander COM sends a command signal of a data transmission request, the remote commander COM enters a reception wait state of the data sent from the main body CNV. When the remote commander receives the data sent from the main body CNV and continues the state till the reception is finished. The operation above is repeated for each data transmission request.