A physical quantity sensor comprising a substrate; a fixed section fixed to the substrate; a movable section displaceable in a first direction with respect to the fixed section; a movable electrode section provided in the movable section; a fixed electrode section fixed to the substrate and disposed to be opposed to the movable electrode section in the first direction; and a restricting section configured to restrict a movable range in the first direction of the movable section, wherein the movable section includes: a first outer edge portion disposed on the first direction plus side of the fixed section along a second direction orthogonal to the first direction; and a second outer edge portion disposed on the first direction minus side of the fixed section along the second direction, and the restricting section includes at least one of: a first restricting section disposed to be opposed to the first outer edge portion via a gap on a side of the first outer edge portion opposite to a side of the fixed section; and a second restricting section disposed to be opposed to the second outer edge portion via a gap on a side of the second outer edge portion opposite to a side of the fixed section, wherein the first restricting section is disposed to extend along an outer edge of the first outer edge portion, and the second restricting section is disposed to extend along an outer edge of the second outer edge portion, characterized in that at least one of the first restricting section and the second restricting section includes a slit (911, 921) and a beam section (912, 922) and thus has elasticity in the first direction. a fixed section fixed to the substrate; a movable section displaceable in a first direction with respect to the fixed section; a movable electrode section provided in the movable section; a fixed electrode section fixed to the substrate and disposed to be opposed to the movable electrode section in the first direction; and a restricting section configured to restrict a movable range in the first direction of the movable section, wherein the movable section includes: a first outer edge portion disposed on the first direction plus side of the fixed section along a second direction orthogonal to the first direction; and a second outer edge portion disposed on the first direction minus side of the fixed section along the second direction, and a first outer edge portion disposed on the first direction plus side of the fixed section along a second direction orthogonal to the first direction; and a second outer edge portion disposed on the first direction minus side of the fixed section along the second direction, and the restricting section includes at least one of: a first restricting section disposed to be opposed to the first outer edge portion via a gap on a side of the first outer edge portion opposite to a side of the fixed section; and a second restricting section disposed to be opposed to the second outer edge portion via a gap on a side of the second outer edge portion opposite to a side of the fixed section, wherein a first restricting section disposed to be opposed to the first outer edge portion via a gap on a side of the first outer edge portion opposite to a side of the fixed section; and a second restricting section disposed to be opposed to the second outer edge portion via a gap on a side of the second outer edge portion opposite to a side of the fixed section, wherein the first restricting section is disposed to extend along an outer edge of the first outer edge portion, and the second restricting section is disposed to extend along an outer edge of the second outer edge portion, characterized in that at least one of the first restricting section and the second restricting section includes a slit (911, 921) and a beam section (912, 922) and thus has elasticity in the first direction.