A consciousness judging apparatus, which detects a vehicle driving state and judges consciousness of a driver, comprising a monotonousness detection section to obtain monotonousness, a camera which captures an image of a road surface in the vehicle running direction, a meander quantity detection section which detects the meander quantity based on the road surface image taken by the camera, a correction section which corrects and increases the monotonousness when the meander quantity detected this time by the meander quantity detection section is larger than the meander quantity detected last time by the meander quantity detection section by the value greater than a predetermined value α, and a fuzzy inference section which infers a driver's consciousness based on the monotonousness corrected by the correction section and meander quantity.