An optical modulator having a junction layer is disclosed. An optical modulator may be provided which includes a substrate, an insulation layer positioned on the substrate, a ribbon layer positioned with an intermediate portion spaced apart from the insulation layer by a predetermined distance, a protective layer positioned on both ends of the ribbon layer, a junction layer positioned on the protective layer which has an adhesive property and which prevents the diffusion of gas, and a piezoelectric element joined with the protective layer by way of the junction layer interposed in-between which moves the intermediate portion of the ribbon layer toward and away from the substrate. In certain embodiments of the invention, the light diffraction property and reliability of the overall optical modulator can be maximized, by positioning a junction layer, having improved adhesion and capable of preventing the diffusion of oxygen, on the lower surface of the piezoelectric elements.