A vehicle and road sign recognition device each includes: image capturing means (2) which captures a color image of a road via imaging means (6); feature value calculation means (4) which calculates a feature value of each pixel corresponding to the color of a road sign on the road from the color components of each pixel in the color image so as to reduce the effect of brightness on the color components; and road sign detection means (5) which detects the road sign on the road from the feature image in which the feature value of each pixel in the color image is arranged so as to match with the position of each pixel in the color image. Thus, it is possible to accurately detect a road sign such as a lane mark from the color image of the road captured via the imaging means such as a camera even if the road illumination state is partially different.