A fuel cell system includes fuel cell apparatuses and an external management apparatus. Each of the fuel cell apparatuses includes a controller that controls the fuel cell apparatus in any of multiple operating modes that include a master mode and a slave mode. The external management apparatus acquires the power consumption of the load, generates control information for controlling an operation state of the fuel cell apparatuses on the basis of the power consumption, and transmits the control information to a fuel cell apparatus operating in master mode. This apparatus controls its own operation state and the operation state of the other fuel cell apparatuses on the basis of the received control information.