To provide the electromagnetic shield structure of a building, an office or the like, by which internal and external communication is enabled by improving only the transparency of radio waves having a specific wavelength used for a portable telephone, a PHS or the like, maintaining high electromagnetic shield performance.

A plurality of electromagnetic shield layers 2 are arranged in parallel and formed, and the mutual clearance L of each electromagnetic shield layer 2 is set in the half-wavelength of radio waves having the specific wavelength to be transmitted or the integral times of the half-wavelength. Since transmitted radio waves are attenuated every time they are passed through a plurality of the electromagnetic shield layers 2, electromagnetic shield performance having high performance is obtained generally even when the attenuation performance of each layer is inhibited. Then, when the mutual clearance L of a plurality of the electromagnetic shield layers 2 arranged in parallel is set in the half-wavelength (L=λa/2) of radio waves having the specific wavelength λa used for the portable telephone and the PHS or the integral times (L=n.λa/2) of the half-wavelength, radio waves having the specific wavelength resonate among a plurality of the layers 2, and the attenuation of the radio waves is inhibited as much as possible and radio waves are transmitted.