Method for manufacturing a magneto-resistance element

The present invention provides a method for manufacturing a magneto-resistance element capable to increase the selectivity of the non-magnetic insulating layer to achieve a highly accurate etching of the ferromagnetic layer. In the production method of A magnetic element according to an embodiment of the present invention, the chlorine-based reactive ion etching using a plasma gas (RIE), MgO layer (non-magnetic insulating layer) on 26 second the second ferromagnetic layer 27 chemically etched. At this time, the substrate temperature by a 100 ° C. or higher 250 ° C. or less, while suppressing the etching of the MgO layer 26, it is possible to enhance the etching of the second ferromagnetic layer 27. Accordingly, while securing a high selection ratio between the MgO layer 26, it is possible to a second ferromagnetic layer 27 are etched.