A lighting device includes a plurality of light-transmitting guide plates 1, 2, 3 laminated in at least three layers and a plurality of light emitting elements 4, 5, 6 arranged so as to oppose to respective lateral sides of the light-transmitting guide plates 1, 2, 3 to allow luminance flux in different color with respect to each light-transmitting guide plate to be incident on the corresponding light-transmitting guide plate. Each of the light-transmitting guide plates 1, 2, 3 has a plurality of reflecting surfaces 7, 8, 9 formed on the backside of the plate to change a propagation direction of the luminance flux propagated in the each light-transmitting guide plate, allowing the luminance flux, of which propagation direction has been changed by the reflecting surfaces 7, 8, 9, to be emitted from the front side of the each light-transmitting guide plates.