A physical quantity sensor includes a support substrate, anchor portions fixed to a top surface of the support substrate, a movable portion positioned above the support substrate and supported by the anchor portions with support portions provided therebetween such that the movable portion is movable in a height direction, and detection portions for detecting a displacement of the movable portion. The support portions include beam portions provided between the movable portion and the anchor portions such that spring portions are provided between the beam portions and each of the movable portion and the anchor portions, the beam portions having a rigidity higher than a rigidity of the spring portions. The movable portion translates in the height direction owing to twisting of the spring portions and displacements in the height direction of distal ends of the beam portions, the movable portion being supported at the distal end.