Abstract
The purpose of this paper is to make clear a screening effect of electromagnetic shielding material with charcoal powder and water. The screening effect of the material was estimated using the Schelkunoff theory. A summary of the results is shown below. (1) The material with charcoal powder and water layer has good screening effect against electromagnetic wave in the range of lOkHz to 100MHz. (2) The water layer between the shielding materials is effective to shield electromagnetic wave. (3) The thickness of the shielding material is not affected on screening effect of electromagnetic waves very much.
