HEAD-UP DISPLAY DEVICE

A head-up display device makes it possible to increase the number of common parts between when mounted in a right-hand-drive car and when mounted in a left-hand-drive car. A head-up display device includes: a first unit which generates display light; and a second unit to which the first unit is attached, and which displays a virtual image by guiding the display light generated by the first unit to a windshield. The first unit is provided with a projector which emits the display light, and a first optical relay which guides the display light from the projector to the second unit along a virtual plane. The second unit is provided with a second optical relay which guides the display light to the windshield such that an irradiation position at which the windshield is irradiated with the display light is shifted in a car width direction crossing the virtual plane.