A liquid crystal display device includes a pair of transparent substrates, a liquid crystal layer sandwiched between inner surfaces of the transparent substrates, and a pair of optical films each attached on an outer surface of the transparent substrate via a transparent adhesive layer. The transparent adhesive layer has an outer surface facing the optical film. The outer surface of each transparent substrate has a first Ra surface roughness, and the outer surface of the adhesive layer has a second Ra surface roughness which is smaller than the first Ra surface roughness. The present invention further provides a method for manufacturing the liquid crystal display device.