One example of a high-frequency filter includes a dielectric substrate having a high dielectric constant. On one whole main face of the dielectric substrate, an earth electrode is formed. On the other main face of the dielectric substrate, two pattern electrodes are formed. The pattern electrodes have first parts formed in parallel at an interval, and second parts extended in crossing (non-parallel) directions. Also, on one main face of the dielectric substrate, input-output electrodes are respectively formed near the end parts of the pattern electrodes, and capacitors are respectively formed between the open end parts and the input-output electrodes.