An MRAM is provided with a memory main body (2) having at least one cell array, and a magnetic field detecting section (4) which detects a magnetic field in the vicinity of the memory main body (2) and outputs the detection signal to the memory main body (2). In the cell array, a memory main body (2), which has a plurality of magnetic memory cells including a multilayer ferri-structure as a free layer, stops a prescribed operation of the memory main body (2), based on the detection signal.