Virtual image display device

A virtual image display device for a vehicle so as to display a virtual image by projecting a display light of an image toward a projection unit, the virtual image display device comprising:

• a display unit configured to emit the display light;
• and
• a horizontal diffraction reflection element configured to reflect the display light emitted from the display unit by diffraction, the horizontal diffraction reflection element having a plate shape along a horizontal plane of the vehicle, wherein
• the horizontal diffraction reflection element is configured to emit the display light toward the projection unit arranged above the horizontal diffraction reflection element when the display light is incident, and
• an angle of incidence on the horizontal diffraction reflection element is larger than an angle of emission from the horizontal diffraction reflection element.