Magnetic thin film memory and recording and reproducing method and apparatus using such a memory

A magnetic thin film memory includes a stack of magnetic thin film devices each comprising a first magnetic layer (11), a second magnetic layer (12) of higher coercive force than the first magnetic layer on the first magnetic layer (11), and a non-magnetic layer (13) between the first magnetic layer (11) and the second magnetic layer (12). A conductive write wire (2; 24) separated from each magnetic thin film device by an insulator enables the application of a magnetic field. A pair of electrodes (4, 5) enables electric current flow through the magnetic layers (11, 12) in order to detect changes in magnetoresistance dependent on information recorded in the devices.