A display device for a transportation includes: a display unit displaying a display image on front and rear face sides, the display images displayed on the rear face side being in mirror image relationship with each other; and an optical member for inverting the display image displayed on the rear face side; wherein the display image displayed on the front face side is directly seen by a driver and the display image displayed on the rear face side is inverted by the optical member, so as to see in the same direction of the display image displayed on the front face side. The above display unit may be constituted by a light source having plural color spectra; an attenuation filter in which a transmittance for light emitted from the light source can be partly changed by an external signal; and a transparent light guide plate which guides light emitted from the light source to at least one of front and rear faces of the attenuation filter.