To provide a liquid metal switch having a high operation speed with less power consuming.

The problem is solved by a relay 100 started in an piezoelectric manner and having: a liquid metal passage 195; first and second fluid chambers 180; first and second films 170 for forming tops of the first and second fluid chambers; first, second and third contact pads 200 each having a part in the passage; a plurality of piezoelectric elements 160 mounted to the respective films for forming first and second sets; and movable conductive liquid in the passage.