SHUT-DOWN METHOD FOR FUEL CELL ELECTRICITY GENERATION SYSTEM

A fuel cell power generation system according to the present invention includes a fuel cell (11), a fuel generator (12), an oxidizing gas supply device (13), an output controller (14), an open-close mechanism, and a controller (20). The controller (20) is configured such that in a stop process, the controller (20): reduces an amount of electric power extracted from the fuel cell (11) and then controls the output controller (14) to stop supplying the electric power to an external load; controls the oxidizing gas supply device (13) to stop supplying an oxidizing gas and controls the open-close mechanism to close a passage upstream from an oxidizing gas channel (2); after the passage upstream from the oxidizing gas channel (2) is closed, stops a raw material gas supply device (16) and a water supply device (15) when a predetermined period has elapsed, during which period a gas in the oxidizing gas channel (2) is replaced by a fuel gas that has cross-leaked to the oxidizing gas channel (2) through an electrolyte membrane (1); and then controls the open-close mechanism to close a passage upstream from a fuel gas channel (1) and a passage downstream the fuel gas channel (1).