PURPOSE: To form a shield being hard for flux leaking from a winding to invade into the tank wall of an electric induction apparatus by a method wherein connecting magnetic shielding plates are provided at the upper and the lower end faces of magnetic shielding plates being provided at the upper and the lower parts of a hole passing a lead wire.

CONSTITUTION: A core 6 and a winding 3 is put at the inside of a tank wall 1, and an opening 5 passing a lead wire 4 are provided. Slender silicon steel bands are adhered piling up plural sheets on the tank wall excluding the upper and the lower parts of the opening 5, narrow paper tablet shaped magnetic shielding plates 2 are provided and short narrow paper tablet shaped magnetic shielding plates 21 are provided at the upper and the lower parts. Transversal magnetic shielding plates 22 connecting the magnetic shielding plates 2, 21 are provided, and the flux generating from the winding 3 passes through the shielding plates 21, 22, 2, 22, 21 and returns to the winding 3. By this way, the magnetic resistance becomes small, and the quantity of leakage flux passing through the tank wall 1 can be reduced.