A liquid crystal display device formed as a both-side liquid crystal display device can suppress the generation of brightness irregularities generated on a main liquid crystal display panel thereof and can display an image with a uniform brightness over the whole screen to an extent that a uniform brightness is obtained in practical use. On a bottom surface of a first recessed portion formed in a casing, an optical sheet is arranged such that the optical sheet bridges over an opening, and a proper amount of color pigment is added to the casing on which the optical sheet is arranged in a contact state, thus making the reflectance wavelength characteristic of the surface substantially equal to the reflectance wavelength characteristic of a portion of the sub liquid crystal display panel.