In relation to reading of data in a memory, it is an object to provide a semiconductor device mounted with a low power consumption memory. A semiconductor device including a word line, a bit line, and a memory cell electrically connected to the word line and the bit line, further includes a precharge circuit for making the bit line have an electric potential for reading data stored in the memory cell. The precharge circuit is provided for each bit line and connected to the bit line. Further, the precharge circuit is capable of making each bit line have an electric potential for reading the data stored in the memory cell for each bit line.