A pressure sensor which includes: a semiconductor substrate; a first cavity portion that spreads out approximately parallel with one surface of the semiconductor substrate in the interior of a central region thereof; a diaphragm portion of a thin plate shape that is positioned on one side of the first cavity portion; a pressure sensitive element that is disposed on the diaphragm; and a bump that is disposed in an outer edge region of the one surface of the semiconductor substrate that excludes the diaphragm portion and is electrically connected with the pressure sensitive element, wherein a second cavity portion is disposed in at least one portion of the outer edge region in the interior of the semiconductor substrate and is closed with respect to the one surface of the semiconductor substrate.