The fuel cell system is a fuel cell system comprising a fuel cell stack assembly, wherein the fuel cell stack assembly comprises a fuel cell stack and a data storage configured to store a start-up history of the fuel cell stack; wherein the data storage comprises a detector configured to detect a presence or absence of a connection to at least one selected from the group consisting of an external power source and an external communication device; and wherein the data storage starts up when a voltage of the fuel cell stack is a predetermined threshold value or more.