A hydrogen generation system may include a burner unit that generates combustion gas and a combustion gas passage through which the combustion gas generated by the burner unit flows. A reformer, having a reforming catalyst, generates a reformed gas containing hydrogen by steam reforming a feed material and steam using the heat from the combustion gas. An evaporator evaporates water into steam using the heat from the combustion gas, flowing through the combustion gas passage, and supplies the steam to the reformer. The combustion gas passage is arranged to cover at least a portion of an outer surface of the reformer, and the evaporator is arranged to cover at least a portion of an outer surface of the combustion gas passage.