A head-up display device includes: an image formation unit which emits light including image information; and a projection optical system including an ocular optical system which displays a virtual image by reflecting the light emitted from the image formation unit. The ocular optical system includes spherical lenses, a free-form curved surface lens, a reflection mirror, and a free-form curved surface mirror, and is configured by arranging, in a space on the side of the ocular optical system of a plane conjugate with the virtual image plane with respect to the ocular optical system, a first small lens system which achieves first focus position movement and on which separated light from the image formation unit is made to be incident, and a second small lens system which achieves second focus position movement and on which separated light from the image formation unit is made to be incident.