In a liquid crystal display device having a light diffuser, a desired luminance distribution is realized and displaying with a high contrast ratio across a broad angle range is performed. A liquid crystal display device according to the present invention includes a liquid crystal display panel for modulating light emitted from a light source, and a light diffuser being disposed at a viewer's side of the liquid crystal display panel. The light diffuser is a prism sheet including a plurality of prisms, each prism having: a first prism section including a first slope slanted at a first angle with respect to the display surface normal direction; and a second prism section including a second slope slanted with respect to the display surface normal direction at a second angle different from the first angle and being disposed at the viewer's side of the first prism section.