A physical quantity sensor includes a substrate, a movable body which has first and second sections and in which a first movable electrode section is provided in the first section, a beam section which supports the movable body so as to be able to be displaced, and a first fixed electrode section disposed on the substrate. The first fixed electrode section is provided at a position overlapping an end of the first section in the second axis direction in plan view, and is provided in a range of 0.0500X≦L≦0.816X assuming that the width of the first section in the second axis direction is X and the width of a portion of the first fixed electrode section in the second axis direction overlapping the movable body in plan view is L.