PURPOSE: To obtain a higher CNR with a very short bit by canceling mutual force-rotation with dual layers film or reinforcing and causing super resolution.

CONSTITUTION: A magnetic domain according to information is recorded on a recording layer 3, and exchange connection is cut by a cut layer 2 between the recording layer and a mask layer l. When the magnetization of the mask layer 1 is constituted so as to face in the same direction as the magnetization direction of the recording layer 3 by static magnetism connection, the force- rotation direction 10 of the mask layer 1 and the force-rotation direction 11 of the recording layer 3 are canceled each other, and a polarizing direction 8 of an incident beam coincides roughly with the polarizing direction 9 of a reflected beam. That is, in such a case, it becomes the state where a regenerative signal hardly be obtained. In such a medium, when a part is heated to a compensation temp. or above by a reproducing beam, the direction of synthetic magnetization 6 becomes inverse in the inside of the layer 1, and the magnetization direction of the layer 1 is inverted, and is arranged with the magnetization direction of the layer 3. Thus, since the force-rotation angle 10 of the layer 1 is inverted, the polarizing direction 9 according to recording is generated.