The present invention provides a liquid crystal display device having a linear light source, which is easily treated, in consideration of the heat radiation of a light-emitting diode in the liquid crystal display using the light-emitting diode as a light source.A light-emitting diode 150 is provided on a metal substrate 161. The metal substrate 161 is formed in a case shape such that the heat generated at the light-emitting diode 150 received in the case is efficiently radiated. A resin material 175 is filled in the metal case to form a plate-shaped light source 130. It is possible to improve reliability during the handling in the manufacturing process by filling the resin material 175 to form the plate-shaped light source. It is possible to improve heat radiation effect by filling the resin material 157.