An image is captured of a region including an eye of a driver using an image capture device 12, and the degree of eye openness is detected with a degree of eye openness detection section 24. A standard closed eye threshold value, a large value closed eye threshold value and a small closed eye threshold value stored in the threshold value storage section 28 are employed by the feature amount extraction section 30 to extract plural types of blinking feature amount from the detected degree of eye openness time series data. Threshold value determination is performed for each of the plural types of blinking feature amount by the threshold value determination section 32, and determination of the state of drowsiness of the driver is made by the drowsiness determination section 34 based on the threshold value determination results for the plural types of blinking feature amount. Accordingly, respective threshold values appropriate to the types of blinking feature amounts are employed in extracting blinking feature amounts, enabling determination of state of drowsiness to be performed with good precision.
