An electromagnetic wave transmission structure adapted to cause convergence of an electromagnetic wave includes a substrate and a transmission unit provided on the substrate and including an annular metal plate. The annular metal plate has a weighted average inner radius and a weighted average outer radius each related to the wavelength of the electromagnetic wave, the distance between the electromagnetic wave transmission structure and a focal point defined as the point of convergence of the electromagnetic wave, and the distance between the source of the electromagnetic wave and the focal point. The plural inner and outer radii of the annular metal plate have the same trend of variation. Each inner or outer radius corresponds to a weight related to the reference included angle formed between the inner or outer radius and a reference axis.