A light emitting device is provided which can prevent a change in gate
voltage due to leakage or other causes and at the same time can prevent
the aperture ratio from lowering. A capacitor storage is formed from a
connection wiring line, an insulating film, and a capacitance wiring
line. The connection wiring line is formed over a gate electrode and an
active layer of a TFT of a pixel, and is connected to the active layer.
The insulating film is formed on the connection wiring line. The
capacitance wiring line is formed on the insulating film. This structure
enables the capacitor storage to overlap the TFT, thereby increasing the
capacity of the capacitor storage while keeping the aperture ratio from
lowering. Accordingly, a change in gate voltage due to leakage or other
causes can be avoided to prevent a change in luminance of an OLED and
flickering of screen in analog driving.