A display device includes a prism sheet between a display cell and a light guiding plate. The prism sheet includes a plurality of prisms having a constant apex angle continuously arranged in a second direction on a surface thereof opposed to a light-exiting surface of the light guiding plate. Each of ridge lines of the prisms extends in a first direction. Each prism has a first inclined face on a side on which light from the light guiding plate is incident and a second inclined face on a side reflecting the incident light. An area of the first inclined face is made smaller than an area of the second inclined face, and an area of a light-emitting region in the prism sheet is made larger than an area of a non-light-emitting region.