There is provided an apparatus for supplying a hydrogen gas to a quartz glass manufacturing apparatus including a burner that generates an oxyhydrogen flame when supplied with the hydrogen gas, where the apparatus includes: a first hydrogen supply system that supplies a hydrogen gas in which isotopes are in equilibrium; a second hydrogen supply system that supplies a hydrogen gas in which isotopes are out of equilibrium; a flow rate control section that includes: a valve that changes a flow rate of the hydrogen gas to be supplied to the burner; a first flow rate measuring section that measures the flow rate of the hydrogen gas to be supplied to the burner by measuring a heat capacity; and a control section that controls the valve in such a manner that a measured value obtained by the first flow rate measuring section approaches a set value input from outside; a second flow rate measuring section that measures the flow rate of the hydrogen gas to be supplied to the burner by measuring a different factor than the heat capacity; and a set value compensating section that compensates the set value by multiplying the set value by a ratio between the measured value obtained by the first flow rate measuring section and a measured value obtained by the second flow rate measuring section.