To provide a method reducing high frequency emission from a computer that performs with frequency particularly in the range of 100 MHz to 1 GHz or more.

The method includes a step in which a lamination layer structure including a metallic layer 513 and dielectric attenuation layer 511 so as to form a transmitting system 515 having electric energy attenuating properties is arranged and kept contact with a conductor layer 507 or dielectric layer 509 being in contact with the conduct layer 507.