An absorbent includes a ferromagnetic nucleus with a one-layer or two-layer shell or devoid thereof and the nucleus is embodied in the form of a plate with a planar size that ranges from 500-5000 μm and the thickness is equal to 0.1-1000 μm. The method for producing the inventive magnetically-operated absorbent includes evaporating and/or melting a magnetic material powder in a low-temperature plasma, quenching and condensing the thus obtained vaporized and/or melt-particle product in a gas flux, and transferring the product precipitated in the form of crystals or micro slugs of corresponding metals, correspondingly to a stabilizer-containing dispersion medium and holding in the medium until a gas release is over. Then the crystals or micro slugs are processed by flattening, for example pressing so that the plates of a specified thickness are obtained.