To provide a hydrogen manufacturing device for simultaneously using a generator, for inexpensively manufacturing hydrogen by a steam reformer, and efficiently generating electric power, by using gas turbine exhaust gas.

This device has a converging detonation generator 1 for generating detonation by intermittent combustion, a gas turbine generator 3 for supplying combustion exhaust gas of the converging detonation genetrator 1, an impactive heater 7 having a processing chamber for storing the exhaust gas of the gas turbine generator 3 and raising the temperature by impactively compressing the gas turbine exhaust gas in the processing chamber by introducing a shock wave from the converging detonation generator 1 to the processing chamber, and the steam reformer 9 for supplying hydrocarbon and steam and generating hydrogen and carbon monoxide with the gas turbine exhaust gas heated by the impactive heater 7 as a heat source.