In the case where a material containing an alkaline metal or an alkaline-earth metal in a cathode, an anode, a buffer layer, or an organic compound layer is used, there is a fear of the diffusion of an impurity ion (representatively, alkaline metal ion or alkaline-earth metal ion) from the EL element to the TFT being generated and causing the variation of characteristics of the TFT.As the insulating films 117, 317 and 417 provided between TFT and EL element, a film containing a material for not only blocking the diffusion of an impurity ion such as an alkaline metal ion and an alkaline-earth metal ion but also aggressively absorbing an impurity ion such as an alkaline metal ion and an alkaline-earth metal ion, for example, a silicon nitride film containing a large amount of fluorine, a silicon oxynitride film containing a large amount of fluorine or an organic resin film containing a particle consisted of an antimony (Sb) compound, a tin (Sn) compound, or an indium (In) compound is used.