A high-frequency device comprises a dielectric substrate (11), a filter element which has a plurality of resonating elements (12) made of a first superconductor film on the dielectric substrate (11), a dielectric plate (16) which faces the dielectric substrate (11) substantially in parallel with the substrate (11) and covers the plurality of resonating elements (12), and a spacing adjusting member (17) configured to control the spacing between the dielectric plate (16) and the dielectric substrate (11). The high-frequency device enables the pass-band frequency of the filter to be adjusted with high accuracy without variations in the skirt characteristic or ripple characteristic. <IMAGE>
