A fuel cell system mounted in a vehicle, the fuel cell system comprising: a fuel cell configured to supply electric power to a motor driving the vehicle; a pump configured to supply oxygen to the fuel cell; and an accelerator position detection unit configured to detect an accelerator depression amount of the vehicle; a control unit configured to calculate, based on the accelerator depression amount, electric power required to be generated by the fuel cell and electric power required for driving of the pump and configured to control the pump based on the electric power required for driving of the pump; and wherein, when the calculated electric power required to be generated by the fuel cell increases, the control unit calculates the electric power required for driving of the pump to have a rate of increase exceeding a rate of increase in the electric power required to be generated by the fuel cell; characterised by: the control unit is configured to determine that a condition for the occurrence of torque shock during acceleration is satisfied when a difference between the electric power required to be generated by the fuel cell and electric power actually generated by the fuel cell is equal to or greater than a first threshold and the electric power actually generated is equal to or less than a second threshold, and, when the condition is determined to be satisfied, to correct a value of the electric power required to be generated by the fuel cell by reducing the value of the electric power required to be generated by the fuel cell by applying a rate limit to the electric power required to be generated by the fuel cell to decrease the difference between the electric power required to be generated by the fuel cell and electric power actually generated by the fuel cell with respect to the electric power required to be generated by the fuel cell calculated based on the accelerator depression amount such that the actual torque does not increase rapidly and the occurrence of torque shock is suppressed. a fuel cell configured to supply electric power to a motor driving the vehicle; a pump configured to supply oxygen to the fuel cell; and an accelerator position detection unit configured to detect an accelerator depression amount of the vehicle; a control unit configured to calculate, based on the accelerator depression amount, electric power required to be generated by the fuel cell and electric power required for driving of the pump and configured to control the pump based on the electric power required for driving of the pump; and wherein, when the calculated electric power required to be generated by the fuel cell increases, the control unit calculates the electric power required for driving of the pump to have a rate of increase exceeding a rate of increase in the electric power required to be generated by the fuel cell; characterised by: the control unit is configured to determine that a condition for the occurrence of torque shock during acceleration is satisfied when a difference between the electric power required to be generated by the fuel cell and electric power actually generated by the fuel cell is equal to or greater than a first threshold and the electric power actually generated is equal to or less than a second threshold, and, when the condition is determined to be satisfied, to correct a value of the electric power required to be generated by the fuel cell by reducing the value of the electric power required to be generated by the fuel cell by applying a rate limit to the electric power required to be generated by the fuel cell to decrease the difference between the electric power required to be generated by the fuel cell and electric power actually generated by the fuel cell with respect to the electric power required to be generated by the fuel cell calculated based on the accelerator depression amount such that the actual torque does not increase rapidly and the occurrence of torque shock is suppressed.