An electrical insulating structure producing method that covers an outer surface of a to-be-insulated object, comprises: a taping step (S01) in which a main insulation tape is wound on the outside of the to-be-insulated object to form a main insulated part; a vacuum drawing step (S03) in which the tape-wound to-be-insulated object is subjected to vacuum drawing, after the taping step (S01); and an impregnation step (S04) in which a nanoparticle-containing impregnating macromolecular polymer, in which nanoparticles have been kneaded, is injected to impregnate the main insulated part therewith, after the vacuum drawing step (S03) .