Provided is an RF passive device ultra-miniaturized in a nanometer scale by inducing a surface plasmon resonance phenomenon by applying a metamaterial having a negative permittivity, and a method for miniaturizing the same. The RF passive device of the present invention includes: a radiator provided on a dielectric substrate; a ground plane onto which a metamaterial constituting each unit resonance cell is applied using a ring resonator of a quasi-Moebius strip structure; and a feed line for electrically connecting the radiator to the ground plane, in which an antenna is provided for inducing the surface plasmon resonance phenomenon between the atmosphere and the ground plane. As such, the surface plasmon resonance phenomenon can be induced by applying, to the ground plane, the metamaterial consisting of a unit resonance cell to which the ring resonator of a quasi-Moebius strip structure is applied.