The present invention is intended to make it possible to set security functions as necessary depending on usage environment, etc. and to improve the security functions; a function setting section 1116 sets security function information received from the outside via a communication line as security functions regarding the user of gas. According to the set security function, in the case that the operation conditions of the security function are satisfied, a monitoring section 112 detects a problem during the use of gas and outputs a security signal to a control section 114. Based on the security signal from the monitoring section 112, the control section 114 shuts off the supply of gas in the case that a phenomenon satisfying an operation condition of the set function having been set has occurred.