The present invention provides a gas control system which introduces carrier gas into a tank containing a material and leads out material gas generated by vaporization of the material from the tank together with the carrier gas, the gas control system being provided with: a flow rate control unit that is configure to control the flow rate of the material gas led out from the tank by adjusting the flow rate of the carrier gas introduced into the tank; and a control limit detection unit that is configured to detect a control limit state and output detection of the control limit state, the control limit state is a state that the adjustment of the flow rate of the carrier gas performed by the flow rate control unit cannot secure the flow rate control of the material gas at a predetermined performance level.