A semiconductor device including a plurality of memory cells arranged in a matrix pattern, a write amplifier which writes write data to the memory cell in synchronization with a clock, a sense amplifier which reads out the write data written in the memory cell in synchronization with the clock, a plurality of column select switches which connect the plurality of the memory cells with the sense amplifier and the write amplifier, a column address decoder which makes the column select switch corresponding to one column among the plurality of the memory cells a conductive state based on a column address, a row address decoder which activates the memory cell of one row based on a row address, and a test write circuit which writes data corresponding to a logical level of a test signal to the memory cell based on a test mode signal.