A physical quantity sensor includes: a substrate; first and second displacement members in a spatial plane on the substrate and having rotation shafts; fixed electrodes on the substrate opposed to the first and second displacement members; a support member supporting the rotation shafts; fixing members supporting the support member via a spring unit; and a driving unit oscillating the support member in an oscillation direction. Each of the first and second displacement members shifts perpendicularly to the spatial plane around an axis of the corresponding rotation shaft. Each rotation shaft is shifted in an opposite direction from the center of gravity of the corresponding displacement member.