PURPOSE: To reduce the cost of the titled device by sharing a high-frequency wave electric power generation circuit and an electromagnetic field generator.

CONSTITUTION: In a device for enriching a gaseous molecule having the specified neuclide by nearly rectangularly acting both a high-frequency wave electric field and a high-frequency wave magnetic field and utilizing the difference of the ratio of degree of polarization and mass of the gaseous molecule, a coil 1 is formed into a closed racing track shape and an electrode 2 is housed in the coil. The electrode 2 is divided into many pieces and each coil and the divided electrode are alternately connected in series. A high-frequency wave electric power circuit is formed by both electrostatic capacity constituting of opposed electrodes and the coil 1 and the electric field and the magnetic field which are generated by these are nearly rectangularly acted in the same space and the gaseous molecule having the specified neuclide is enriched by utilizing the polarization function of the gaseous molecule.