PURPOSE: To enable a material with a sheet-like high magnetic loss and the characteristics to be changed freely by constituting a magnetic micro body in needle-like chain status and by forming an electromagnetic wave material in plate or sheet with an adhesive using this needle-like chain status magnetic micro body.

CONSTITUTION: By introducing a specified amount of magnetic micro body P into magnetic field of a rotary drum 11 where magnetic force is being generated to constitute the micro body P in a needle-like chain status P1 by a magnetic force generating body 12. And then, the magnetic micro body P1 in needle-like chain status is densely filled by increasing the speed of the rotary drum 11 gradually and by applying pressure to the magnetic micro body P1 in needle-like chain status with the centrifugal force. In this case, the centrifugal force is changed by the speed of the rotary drum 11 and the degree of density filling the needle-like chain magnetic micro body P1 is change. It allows the material with a large-sheet and plate-like high magnetic loss and the characteristics to be changed freely and an electromagnetic material with stable performance to be obtained over wide range.