A width and a thickness of a bit line are represented as W1 and T1, respectively, a thickness of a digit line is represented as T2, and a distance from a center of the digit line in a thickness direction to a center of a free layer of an MTJ element in the thickness direction is represented as L1. A width of the digit line is represented as W2, and a distance from a center of the bit line in the thickness direction to the center of the free layer of the MTJ element in the thickness direction is represented as L2. The distances L1 and L2 and the cross-sectional areas S1 and S2 are set in such a manner that when L1/L2.gtoreq.1, a relation of (1/3)(L1/L2 ).ltoreq.S2/S1.ltoreq.1 is satisfied and when L1/L2.ltoreq.1, a relation of 1.ltoreq.S2/S1.ltoreq.3(L1 /L2) is satisfied.