Fuel cell system

A fuel cell system comprising:

• a reformer configured to generate a reformed gas from a raw material gas, water, and air that are supplied to the reformer, the reformed gas serving as a fuel gas;
• a fuel cell configured to generate electric power through a power-generating reaction by utilizing the fuel gas and air;
• a combustor configured to combust an anode off gas, the anode off gas being the fuel gas that has not been utilized in the fuel cell;
• a casing part housing at least the reformer, the fuel cell, and the combustor, which are covered with a heat insulating material;
• and
• a desulfurizer configured to remove a sulfur component from the raw material gas supplied thereto by hydrodesulfurization, wherein
• the anode off gas is supplied to the combustor and the desulfurizer in a distributed manner, and
• the desulfurizer performs the hydrodesulfurization of the raw material gas by utilizing the supplied anode off gas as a hydrogen source and utilizing an exhaust gas discharged from the casing part as a heat source, the exhaust gas containing at least combustion heat from the combustor.