To provide a backlight unit without generating a sticking phenomenon with a deflection film and hardly causing luminance irregularity on the whole screen of a liquid crystal display device.

A resin sheet 4 having non-smooth front and rear side surfaces and transmitting light through is provided between a light control sheet 3 and a deflection film. By providing a bead layer, in which a resin bead is dispersed in a resin binder, on the front and the rear sides of a base material, the front and the rear side surfaces of the resin sheet 4 are made to be non-smooth surfaces. The base material is composed of a biaxially stretching resin film. The direction of optical axis of the base material is made coincident with or orthogonal to the direction of optical axis of a light control sheet 3.