PURPOSE: To improve shielding capacity of a periphery of a superconductor and to realize a magnetic shielding device having a light weight and a small size by disposing a cover member made of a ferromagnetic material so as to be superposed on the periphery of a plate made of the superconductor.

CONSTITUTION: Since a magnetic flux is attracted to a cover member 2 made of a ferromagnetic material arranged on a periphery of a plate 1, a surface magnetic field of the plate 1 made of a superconductor disposed under the member 2 becomes considerably small. As a result, a shielding current density generated at the periphery of the plate 1 can be reduced, and loss of a superconducting state of the part can be prevented. Accordingly, according to the plate for this magnetic shield, even if the plate has a small critical current density or is thin, excellent shielding performance can be achieved. The plate 1 is reduced in thickness thereby to reduce a manufacturing cost, a weight and a size of a magnetic shielding device.