Provided is an electromagnetic wave transmission sheet having a mesh-shaped electrode. The sheet has a length of width in a direction vertical to the propagation direction of the transmitted electromagnetic wave which length is substantially identical to half of the wavelength of the transmitted electromagnetic wave multiplied by a natural number so that a resonance state is obtained in the vertical direction. It is preferable that the sheet have an electromagnetic wave absorbing medium for reducing reflection of the transmitted electromagnetic wave in the propagation direction, so as to eliminate the need of an electromagnetic wave absorbing medium for reducing reflection in the direction vertical to the propagation direction of the transmitted electromagnetic wave.