A driver state determination apparatus includes: a vehicle behavior information acquisition unit that acquires behavior information of a vehicle; an image information acquisition unit that acquires image information including a face of a driver; a reference value setting unit that sets a reference value based on the behavior information of the vehicle acquired by the vehicle behavior information acquisition unit; and an index value calculation unit that calculates an index value relating to a driving state of the driver using duration of a state in which an amount of change in the image information acquired by the image information acquisition unit is equal to or less than the reference value. The apparatus further includes a determination unit that determines that the driver is in an unconscious state when the index value calculated by the index value calculation unit is equal to or greater than a threshold value.
DRIVER STATE DETERMINATION APPARATUS, DRIVER STATE DETERMINATION METHOD, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM