A semiconductor device comprising: a first line; a second line; a third line (Dout); a fourth line (Din); and a memory cell comprising a first transistor and a second transistor, a capacitor; wherein the first transistor comprises: a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode in electrical contact with the first semiconductor film; a first drain electrode in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, wherein the second transistor comprises: a third gate electrode; a third insulating film over the third gate electrode; a second semiconductor film over the third insulating film; a fourth insulating film over the second semiconductor film; a second source electrode in electrical contact with the second semiconductor film; and a second drain electrode in electrical contact with the second semiconductor film, wherein the first gate electrode of the first transistor is electrically connected to the first line, wherein the third gate electrode of the second transistor is electrically connected to the second line, wherein one of a source electrode and a drain electrode of the first transistor is electrically connected to the third line (Dout), wherein one of a source electrode and a drain electrode of the second transistor is electrically connected to the fourth line (Din), wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to the second gate electrode of the first transistor, wherein one of a pair of electrodes of the capacitor is electrically connected to the second gate electrode of the first transistor, and the other of the pair of electrodes of the capacitor is supplied with a fixed potential and electrically connected to the other of the source electrode and drain electrode of the first transistor, and wherein the second semiconductor film includes an oxide semiconductor. a first line; a second line; a third line (Dout); a fourth line (Din); and a memory cell comprising a first transistor and a second transistor, a capacitor; wherein the first transistor comprises: a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode in electrical contact with the first semiconductor film; a first drain electrode in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, a first gate electrode; a first insulating film over the first gate electrode; a first semiconductor film over the first insulating film; a first source electrode in electrical contact with the first semiconductor film; a first drain electrode in electrical contact with the first semiconductor film; a second insulating film over the first semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode over the second insulating film, wherein the second transistor comprises: a third gate electrode; a third insulating film over the third gate electrode; a second semiconductor film over the third insulating film; a fourth insulating film over the second semiconductor film; a second source electrode in electrical contact with the second semiconductor film; and a second drain electrode in electrical contact with the second semiconductor film, a third gate electrode; a third insulating film over the third gate electrode; a second semiconductor film over the third insulating film; a fourth insulating film over the second semiconductor film; a second source electrode in electrical contact with the second semiconductor film; and a second drain electrode in electrical contact with the second semiconductor film, wherein the first gate electrode of the first transistor is electrically connected to the first line, wherein the third gate electrode of the second transistor is electrically connected to the second line, wherein one of a source electrode and a drain electrode of the first transistor is electrically connected to the third line (Dout), wherein one of a source electrode and a drain electrode of the second transistor is electrically connected to the fourth line (Din), wherein the other of the source electrode and the drain electrode of the second transistor is electrically connected to the second gate electrode of the first transistor, wherein one of a pair of electrodes of the capacitor is electrically connected to the second gate electrode of the first transistor, and the other of the pair of electrodes of the capacitor is supplied with a fixed potential and electrically connected to the other of the source electrode and drain electrode of the first transistor, and wherein the second semiconductor film includes an oxide semiconductor.