It is aimed to realize a sleepiness sign detection apparatus with a wide operating condition range for detecting a sign of sleepiness of a vehicle driver, a machine operator, and the like, before they become aware of sleepiness. According to a sleepiness sign detection apparatus 10, a head movement is detected by a head movement detection unit 11, an eye movement is detected by an eye movement detection unit 12, an ideal eye movement angular velocity is calculated by an ideal eye movement angular velocity calculation unit 13 on the basis of head movement data detected by the head movement detection unit 11, an eye-rotation angular velocity is calculated by an eye-rotation angular velocity calculation unit 14 on the basis of eye movement data detected by the eye movement detection unit 12, vestibule-ocular reflex is detected by a sleepiness sign detection unit 15 from the ideal eye movement angular velocity and the eye-rotation angular velocity, and thereby, a sign of sleepiness of a vehicle driver, a machine operator, and the like before they become aware of sleepiness, can be determined by the sleepiness sign detection unit 15 based on the vestibule-ocular reflex.
