In the display device which is used in a miniaturized portable equipment, when a drive circuit is also connected on the same substrate as pixels, an input signal of low voltage has a level thereof shifted even when the threshold value is large or fluctuated. The display device includes pixel electrodes, switching elements which supply video signals to the pixel electrodes, and a drive circuit which supplies the video signals to the switching elements on the same substrate, wherein the drive circuit includes a level shift circuit, the level shift circuit includes a transistor. In a state that the transistor assumes an ON state, when an input signal is inputted to a source terminal and the input signal is at a low voltage level, a drain terminal assumes a low voltage level. Further, even when the input signal is at a high voltage level equal to or lower than a threshold value, the drain terminal outputs a voltage equal to or more than the threshold value as a high level voltage.