Provided is a semiconductor device including first to fifth circuits. The first circuit includes first and second transistors. The second circuit is capable of supplying one of first and second wirings with a gradually changing potential. The third circuit is capable of supplying a predetermined potential to the other of the first and second wirings and is capable of reading data stored in the first circuit. The fourth circuit is capable of comparing first data to be written to the first circuit with second data read by the third circuit. When a comparison result obtained by the fourth circuit concludes that the first data is consistent with the second data, the fifth circuit disconnects the second circuit from the first circuit, and a potential of the one of the first and second wirings is supplied to a gate of the second transistor.