GAS SHUTOFF DEVICE

PROBLEM TO BE SOLVED: To prevent an extra operation other than a measurement in a case where the measurement of instrumental error cannot be enforced in an assembling factory and is enforced in a measurement office, etc.SOLUTION: A gas shutoff device includes a pressure detection means 21, a pressure abnormality determination part 22, a quake-sensing means 23, an earthquake determination part 24, a mask instruction input means 25, a pressure quake-sensing mask part 26, a valve drive part 27, a valve 28, a mask period counting part 29, a forced release input means 30, a flow amount detector 31, a flow amount calculation part 32, and an integration part 33. After a pressure quake-sensing mask function is set, when a given period passes in the mask period counting part 29 or in the difference between a reference integrated value and an integrated value becomes a prescribed value or more in the pressure quake-sensing mask part 26, the pressure quake-sensing mask function is automatically released and also the integration of the integration part 33 is stopped when the pressure quake-sensing mask condition and a pressure decrease condition, thereby achieving both convenience and safety.