FUEL CELL SYSTEM

A fuel cell system includes a target pressure value for the pressure in a fuel cell is set depending on a demand output value to the fuel cell, A turbine retains a set pressure line representing a relationship between an airflow rate supplied to the turbine and a pressure ratio corresponding to a ratio of a pressure upstream of the turbine and a pressure downstream of the turbine. A controller executes a first control when the target pressure value for the fuel cell is lower than the set pressure line and executes a second control when the target pressure value for the fuel cell is higher than the set pressure line. The controller controls an outlet valve so as not to be fully opened when a turbine bypass valve is fully closed.