A fuel cell system (1), especially in a motor vehicle, includes at least one fuel cell (2) for generating electricity, at least one reformer (3) for generating a reformat gas, a fuel supply means (13) for feeding fuel to the reformer (3), a recycling means (83), which has a recycling line (31) connected to the reformer (3) for feeding anode waste gas of the fuel cell (2) to the reformer (3), and an air supply means (17), which has an air line (18) connected to the reformer (3) separately from the recycling line (31) for feeding air to the reformer (3). To increase performance, the fuel supply means (13) may be designed such that fuel can be introduced with it into the recycling line (31).