In a vehicle-mounted image recognition apparatus, a resolution of an image projected on an imaging plane of an image sensor is different at a position away from a center between a circumferential direction and a radial direction. To make a circumferential resolution higher than a radial resolution, at least a lower half of the imaging plane is located closer to a circumferential focus than a middle of a radial focus and the circumferential focus at a position off the optical axis center of the image projected on the image sensor through the image-forming optical system. This is achieved by adjusting the position of the imaging plane when manufacturing or by selecting a lens with high circumferential resolution. This apparatus improves recognition accuracy in recognizing traffic lanes without using an expensive lens exhibiting high resolution both in the circumferential direction and in the radial direction.