In order to suppress the influence of deterioration of a light emitting element resulting from a change over time, the present invention provides a light emitting device in which an electrical circuit for flowing a constant charge between both electrodes of the light emitting element is provided in each pixel. In addition, the present invention provides a light emitting device in which a transistor provided in each pixel is operated in a linear region and used as only a switch, so that the light emitting device is not influenced by a variation in characteristic of the transistor.