A light emitting device capable of preventing a luminance of individual light emitting elements from being fluctuated by applying electrical characteristics of TFTs for properly controlling current being fed to individual light emitting elements, and also capable of generating the constant luminance without adversely being affected by possible degradation of organic light emitting layers and variable temperature by way of preventing the luminance of light emitting elements from being lowered through degradation of organic light emitting layers. Instead of controlling the luminance of light emitting elements by means of a voltage applied to TFTs, by way of properly controlling current flowing into TFTs via a signal-line driving circuit, it is possible to hold on the current flowing into light emitting elements at a desired value without adversely being affected by electrical characteristics of TFTs. Further, a voltage biasing in an inverse direction is fed to light emitting elements per predetermined period of time. The above-described double means multiply such practical effects to more securely prevent the luminance from being lowered by possible degradation of organic light emitting layers, and make it possible to hold on such current flowing into light emitting elements at a desired value without being affected by electrical characteristics of TFTs.