To suppress variations of a vacuum pressure atmosphere in a physical sensor, a physical sensor in which a sensing part that measures a physical quantity is provided in a vacuum space, includes a sensor part in which a plurality of substrates are stacked, and a cavity substrate 9 having a space and provided on an upper surface side or a lower surface side of the sensor part by bonding, wherein the sensing part communicates with a space of the cavity substrate via a ventilation passage 11a provided in the sensor part.