A physical quantity sensor includes a vibration element that performs drive vibration, an acceleration detection chip that detects an acceleration, a semiconductor element which is electrically connected to at least one of the vibration element and the acceleration detection chip, and a package that has a storage space for storing the vibration element, the acceleration detection chip and the semiconductor element. The semiconductor element is fixed to the package, the acceleration detection chip is fixed to the package with the semiconductor element interposed therebetween, and at least a portion of the acceleration detection chip overlaps the vibration element when the package is seen in a plan view.