A challenge to be met by the present invention is to enable appropriate setting of safety function according to a use environment and enhance safety function. An IC card (118) stores data pertaining to the quantity of available gas and at least one safety function program. An IC card reading unit (122) reads information stored in the IC card (118). From the read information, an IC card determination unit (126) determines whether or not the IC card (118) is normal. A safety function detection unit (128) detects a safety function program from the read information and stores the program in a safety function storage unit (130). When the IC card (118) is normal, a function setting unit (116) imparts a safety function program to a monitoring unit (112). A remaining available quantity count unit (124) determines a remaining quantity of available gas from the read quantity of available gas and a flow determined by a flow computing unit (110). A control unit (114) cuts off a gas supply when an event fulfilling operating conditions for safety function has arisen and when the remaining available quantity has come to a predetermined remaining quantity.