Magnetoresistive effect element

A magnetic memory device comprising a memory cell provided with a magnetoresistive effect element as a memory element,

• wherein the magnetoresistive effect element comprises:
• a first ferromagnetic layer formed above a substrate;
• a second ferromagnetic layer formed above the first ferromagnetic layer;
• a first metal oxide layer interposed between the first ferromagnetic layer and the second ferromagnetic layer;
• and
• a second metal oxide layer interposed between the first metal oxide layer and the second ferromagnetic layer and in contact with a surface of the first metal oxide layer on the side of the second ferromagnetic layer, the second metal oxide layer containing the same metal element as the first metal oxide layer in a greater proportion than the first metal oxide layer.