Hydrogen generating apparatus that is capable of controlling the amount of hydrogen generation. The hydrogen generating apparatus in accordance with an embodiment of the present invention has an electrolyzer, a first electrode, a second electrode, a variable resistance, which is located between the first electrode and the second electrode, a flow rate meter, which measures an amount of hydrogen generation in the second electrode, and a variable resistance controller, which receives a set value, compares the amount of hydrogen generation measured by the flow rate meter with the set value, and controls a resistance value of the variable resistance. The amount of hydrogen generation can be controlled by use of variable resistance.