To solve the problem wherein the weight of a conventional MHD generator that uses a single gas becomes heavy, and, in particular, to provide a system suitable for airplanes.

A doughnut-shaped porcelain tube is filled with NO2 and He. A plasma generator by a saddle-shaped coil is provided at one end, and a compressor at the opposite side. A wave-shape coil is wound on the outside wall of the tube, to absorb electricity. Oil is put into the saddle-shaped coil and a coil leading to the compressor. Insulating sections are provided at a portion of the coils. A pump at the center drives out the oil and a battery feeds electricity to generate electric power.