PURPOSE: To obtain an insulated coil for high tension rotating machine having a superior characteristic at a low price by a method wherein insulated elemental wires are transposed and are assembled, and the group of the elemental wires is covered with a porous insulator, a mica tape and a protective tape consisting of a porous insulator are wound around and gap parts are filled up with a thermosetting resin.

CONSTITUTION: Plural insulated elemental wires 1 being transposed the level are arranged in a line constitution putting interline insulators 2 between them, the upper and the lower sides are pressed with transposition under members 4 and porous insulators 10 are provided on them. The whole of this line constitution is surrounded with a porous insulating layer 7, and gaps generating at the circumference of the insulators 10 are filled up with a compound 30. Then a mica tape layer 5 is wound around the outer circumference of the layer 7 and a protective tape layer 6 consisting of a porous insulator is wound on it. In this constitution, a thermosetting resin is contained in the compound 30 and a polyester nonwoven fabric or a polyester cloth glass cloth, etc., are used as the porous insulator 10. By this way, the efficiency of work is improved and a coil having a superior electric, thermal and mechanical characteristic can be obtained.