In order to improve the electromagnetic environment associated with the widespread use of electronic devices for communication, computation, automation, among other purposes, the present paper has developed a carbon plate that exhibits polarization characteristics. To achieve polarization characteristics in the far field, slits were cut into the surface of a carbon plate; termed the slit carbon plate. The value of the RF magnetic shielding degree SD HP when holding the slits of the carbon plate perpendicular to the ground, in the frequency region of 140 MHz to 700 MHz, increased with frequency, and displayed a value of 35 dB at 700 MHz. It was also shown that the value of SD HH , when aligning the slits horizontal to the ground, increased with frequency, and recorded a value of 5 dB at 700 MHz. Namely, the difference in the shielding degrees of the slit carbon plate for the orientation of the slits indicated polarization characteristics. In present research, the polarization characteristics of the slit carbon plate were improved, in the frequency region of 1 MHz to 800 MHz, by the superposition of slit ferrite and copper plates over the slit carbon plate; termed compound plate. For example, the difference between the values of SD HP and SD HH for the compound plate at 30 MHz was found to be improved by approximately 50 dB. In addition, important criteria are discussed for the design of a plate having polarization characteristics, for effective RF magnetic shielding.