A wideband ultra-high refractive index mesoscopic crystal structure including: a first layer with high-conductivity unit bodies arranged in a matrix form, and a low-conductivity material disposed between the high-conductivity unit bodies; a second layer with high-conductivity unit bodies arranged in a matrix form, and a low-conductivity material disposed between the high-conductivity unit bodies; a first shield layer existing between the first and second layers and made of a low-conductivity material; and a second shield layer made of a low-conductivity material disposed on a side of the second layer such that the second layer is disposed between the first shield layer and the second shield layer, wherein the high-conductivity unit bodies in the first layer overlap the high-conductivity unit bodies arranged in the second layer, and wherein the first layer, the first shield layer, the second layer, and the second shield layer are sequentially stacked one or more times.