FUEL CELL SYSTEM AND OPERATION METHOD THEREOF

A controller (81) in a fuel cell system (1A) operates a fuel cell (60) in a normal mode or in a special mode which is switched by the controller (81); in which in the normal mode, the fuel cell (60) is operated so as to satisfy at least one of a first operation condition and a second operation condition, the first operation condition being a condition in which an operation time of the fuel cell per unit period is equal to or shorter than a unit allowable operation time defined based on a total durable operation time of at least one of the fuel cell and the auxiliary device, the second operation condition being a condition in which the number of times of operation of the fuel cell per unit time is equal to or less than a unit allowable number of times of operation defined based on a total durable number of times of operation of at least one of the fuel cell and the auxiliary device, and in the special mode, the fuel cell (60) is operated without being limited by at least one of the first operation condition and the second operation condition.