A head-up display device includes an image module, a substrate, and an optical film. The image module has an emitting source, wherein the emitting source transmits at least one image. The substrate is disposed corresponding to the image module. The optical film is disposed on the substrate and includes at least one transmission layer, wherein each transmission layer has a plurality of transmitting column structures obliquely arranged side by side, and a longitudinal direction of the transmitting column structure has a tilt angle with respect to a normal of the substrate. The at least one image is transmitted to the optical film, and the obliquely disposed transmitting column structures cause the at least one image to scatter on the optical film.