The semiconductor device of the present invention comprises first and second transistors and first and second capacitors. One of source and drain electrodes of the first transistor is electrically connected to a first wiring, the other is electrically connected to a second wiring, and a gate electrode of the first transistor is electrically connected to one of a source electrode and a drain electrode of the second transistor and one of electrodes of the first capacitor. The other of the source and drain electrodes of the second transistor is electrically connected to the first wiring, and a gate electrode of the second transistor is electrically connected to one of electrodes of a second capacitor and a fifth wiring. The other electrode of the first capacitor is electrically connected to a third wiring, and the other electrode of the second capacitor is eclectically connected to a fourth wiring.