A semiconductor device according to an embodiment includes first to fifth interconnects, first to third memory cells, and a control circuit. The control circuit is configured to execute machine learning. Each of the first memory cells, the second memory cells, and the third memory cells includes a resistance changing element. In the machine learning, the control circuit is configured to: execute a write operation using a common write voltage to each of the second memory cells; and after the write operation, input input data to each of the first interconnects, and change a resistance value of at least one third memory cell of the third memory cells based on the input data and a signal output from each of the fifth interconnects based on the input data.