PROBLEM TO BE SOLVED: To enable a driver to have a vigilance effect for a longer time.SOLUTION: A vigilance maintaining system used in a vehicle comprises: a trigger detection unit 401 which detects a trigger to generate a vigilance stimulation； and a stimulation control unit 402 which generates, when the trigger detection unit 401 detects a trigger, vigilance stimulation from stimulators such as a display device 42, an audio output device 43, a vibrator 44, an air conditioning unit, an aroma unit and the like generating different kinds of stimulation to maintain vigilance of a driver of the vehicle. The stimulation control unit 402 performs rotation of strength of the vigilance stimulation of each stimulator in order, and fluctuation of strength of the vigilance stimulation of each stimulator.SELECTED DRAWING: Figure 2
