In a magnetic oxide thin film, at least three phases including a layered antiferromagnetic metallic phase, an antiferromagnetic charge-ordered insulating phase, and a ferromagnetic metallic phase coexist. A magnetic memory element includes the magnetic oxide thin film and an electrode. Therefore, the magnetic oxide thin film and the magnetic memory element can attain, in a form of thin-film (which is necessary to form a device), (i) an enormous resistance change and history dependence at a low resistance and (ii) history dependence of magnetization under a weak magnetic field, without narrowing a range of operating temperature.