In an electromagnetic cloaking structure, a refractive index distribution has a high refractive index region which is provided around a shielding space and has a maximum value in a plane surrounding the shielding space and in which a refractive index decreases gradually from the centroid of the shielding space along a radial line passing through the plane so as to be close to an average refractive index and a low refractive index region which has a minimum value at two points having the shielding space and the high refractive index region interposed therebetween on a virtual optical axis passing through the shielding space and in which the refractive index increases gradually from the two points in a direction opposite to the high refractive index region on the virtual optical axes, on which the two points are placed, so as to be close to the average refractive index.