A physical quantity sensor includes a substrate, a support portion fixed to the substrate, a movable body which is displaceable in a first direction with respect to the support portion and has a movable electrode provided therein, and a fixed electrode fixed to the substrate. The fixed electrode includes first and second fixed electrode fingers positioned on one side of the support portion, third and fourth fixed electrode fingers positioned on the other side thereof. The movable electrode includes first to fourth movable electrode fingers which face the first to fourth fixed electrode fingers in the first direction, respectively.