To provide a data input apparatus which does not display a screen for data input during driving and displays the screen for data input only while stopping.

In the data input apparatus for selecting and inputting one desired candidate from among a plurality of candidates, data are entered without the candidates displayed on the screen during driving, and data are entered with the candidates displayed on the screen while stopping. The candidates are, for example, sequentially selected and read out from among a group of candidates during driving, and a determining operation is performed to input data when the desired candidate is read out. The candidates are sequentially selected and displayed from among the group of candidates while stopping, and an determining operation is performed to input data when the desired candidate is displayed.