PURPOSE: To avoid local overheating caused by a connection wire and make the end support stable by a method wherein upper and lower lead-out parts of a tap- winding are provided to the front and back sides to reduce the number of wires at the lead-out part to a half.

CONSTITUTION: A tap-winding is formed by winding (n) wires and led out from upper and lower lead-out parts. The (n) wires are divided into 1/2(n) and led out from an upper front side 5, a lower front side 6, an upper back side 7 and a lower back side 8 so that the current which flows through a connection wire by which the winding is connected to a tap-changer is reduced to a half. Because the height of an insulator 10 fixing the end of the winding is reduced to a half, its inclination is also reduced to a half. The height of the insulator 10 supporting the tap-winding along the axial direction is reduced and the height H2 of the whole winding is reduced and made compact so that the quantity of the insulator is made uniform all over the circumference and the tap-winding with a sufficient strength against a short circuit mechanical force produced by the short circuit of the electric apparatus such as a transformer.