We propose a high-performance inductor based on the concept of a high-impedance surface (or artificial magnetic conductor). The inductor is shielded from the silicon substrate by a high-impedance surface consisting of a lumped capacitor and inductor. Theoretical calculations comparing the proposed inductor with a conventional inductor shielded by an ordinary metal surface show that the resonant frequency and quality factor (Q) in the millimeter-wave region are higher for the proposed inductor.