A fuel cell power generation system 100 includes a mechanism for detachably holding an adsorptive desulfurization section 5 for adsorbing a sulfur component in a hydrocarbon-based raw material; a reformer for generating hydrogen-containing gas from the raw material which has passed the adsorptive desulfurization section 5; a fuel cell 8 for generating power using the hydrogen-containing gas as a fuel; a raw material supply section 4 for controlling a flow rate of the raw material to be supplied to the adsorptive desulfurization section 5; and an operating control section for controlling a behavior of the raw material supply section 4 and a behavior of the fuel cell 8. When the adsorptive desulfurization section 5 is detected to have been exchanged, the operating control section 16 controls at least one of the behavior of the raw material supply section 4 and the behavior of the fuel cell 8, such that a ratio of the flow rate with respect to a target value for power generation by the fuel cell 8 is temporarily higher than the ratio of the flow rate with respect to the target value for the power generation before the exchange.