Abstract: Disclosed is a transformer of a large capacity for an ultra-high voltage which comprises a core leg coaxially wound sequentially with at least a low voltage winding, a high voltage winding composed of an upper and a lower winding section operated in a parallel connection and having a lead conductor led out from a center portion of the high voltage winding and extending to a terminal to be connected to a high voltage transmission line as well as connection leading-out wires taken out from the top and bottom end portions of the high voltage winding, and an upper and a lower tap winding disposed vertically spaced from each other with a predetermined distance and respectively connected to the upper and lower winding sections of the high voltage winding so as to be operated in a paralled connection therewith.