PURPOSE: To provide superior shield effect and to obtain a very inexpensive magnetic shield plate as well by a method wherein a high-permeability alloy layer composed iron and nickel as a main body is formed on a substrate composed iron as a main body and a mgnetic shield plate is composed.

CONSTITUTION: Nickel plating is directly applied on a substrate composed of iron as a main body. Then, annealing treatment is applied to a base metal coated nickel plating at 750W950°C under nonoxidizing atmosphere to obtain a shield plate. The iron of the base metal diffuses to nickel on the surface of the substrate and a high-permeability alloy layer composed iron and nickel as a main body is formed on the surface of the shield plate. In this way, the shield effect equivalent to a permalloy of 45% is provided and a very inexpensive shield plate can be obtained.