A hydrogen generator including a raw material supplying unit supplying a raw material containing a sulfur component and composed of an organic compound, a water supplying unit supplying water, a reformer producing hydrogen gas, the reformer provided with a reforming catalyst to make the raw material and water undergo a reaction, and a carbon monoxide removing unit reducing the content of carbon monoxide in hydrogen gas produced in the reformer, wherein the reforming catalyst is constituted by a carrier composed of platinum and a metal oxide is provided.