An approach position input device includes a plurality of antennas arranged in the form of a lattice. An oscillator applies a high-frequency ac voltage to the antennas. A signal processing circuit processes signals from the antennas. A change-over switch including switching elements sequentially changes over a connection between the antennas and the signal processing circuit. CPU sends a selection signal to the change-over switch for antenna selection. CPU calculates an approach position of a human body according to signals from the signal processing circuit. CPU instructs the change-over switch to apply the ac voltage from the oscillator only to the antenna selected according to the selection signal.