A data selection line (write line) is disposed right on a MTJ element. Upper and side surfaces of the data selection line are coated with yoke materials which have a high permeability. The yoke materials are separated from each other by a barrier layer. Similarly, a write word line is disposed right under the MTJ element. The lower and side surfaces of the write word line are also coated with the yoke materials which have the high permeability. The yoke materials on the lower and side surfaces of the write word line are also separated from each other by the barrier layer.