A control device of a fuel cell system does not execute feedback control of an air valve in a case where a first condition in which a valve opening degree command value calculated by the control device is less than a command value threshold and a second condition in which a valve opening degree measurement value measured by an air valve opening degree sensor is less than a measurement value threshold are satisfied, and executes the feedback control of the air valve in a case where the first condition or the second condition is not satisfied.