Abstract: In order to basically solve the problem of the change with time of a standard barometric pressure including a vacuum in a standard pressure chamber of a separated type pressure gauge, provided is a separated type pressure gauge in which even if the atmospheric pressure in a standard pressure chamber of the separated type pressure gauge fluctuates due to, for example, the change with the passage of time, a standard barometric pressure in the standard pressure chamber is measured and can be calibrated. In the separated type pressure gauge having a standard pressure chamber, a heat conduction type barometric sensor is equipped in the standard pressure chamber, and the atmospheric pressure in the standard pressure chamber is measured constantly or as necessary to use the measured atmospheric pressure as a standard barometric pressure. The heat conduction type sensor uses a silicon substrate and includes an absolute temperature sensor.