Abstract: A planar illumination device according to an embodiment includes a substrate, a first optical element, a second optical element, a third optical element, a pair of fourth and fifth optical elements, and a sixth optical element. A plurality of light sources are two-dimensionally arranged on the substrate. The first optical element is arranged at an emission side of the plurality of light sources to condense light emitted from the plurality of light sources. The second optical element is arranged at an emission side of the first optical element to tilt light distribution of the light condensed by the first optical element in a first axial direction within an emission surface. The third optical element is arranged at an emission side of the second optical element to spread the light tilted by the second optical element in the first axial direction.