The invention relates to magnetic material physics and to medicine, in particular to magnetotherapy (hyperthermal electromagnetic therapy) of malignant neoplasms. The inventive methods consists in injecting a material particles exhibiting a high-(maximum) magnetocaloric effect into a tumor, wherein said material has a magnetic ordering temperature close (approximately) to a human body temperature and is selected from a group containing precious metals, rare-earth elements (metals) and the alloys or intermetallic compounds thereof. Said method makes it possible to destroy cancer cells without damaging healthy cells and is selected such that it is ecologically pure and non-toxic.
