A fuel cell system includes a battery, a fuel cell, an air pump, and a processor. The battery stores electric power. The fuel cell supplies electric power to the battery. The air pump is driven with the electric power supplied from the battery to supply air to the fuel cell. The processor, when starting the fuel cell system, is configured to compare an amount of the electric power stored in the battery with a threshold electric power. If the amount of the electric power is higher than or equal to the threshold electric power, the air pump is driven. If the amount of the electric power is lower than the threshold electric power, the air pump is prohibited to drive.