A fuel cell system comprising: an acquirer configured to acquire a total value of cell voltages of two or more cells included in a fuel cell; and a determiner configured to: determine, when the total value is a first voltage value, abnormal power generation in which power generation by at least a part of the two or more cells is abnormal and perform output limitation such that generated power in the fuel cell does not exceed an upper limit value, determine, when the total value is a second voltage value higher than the first voltage value, normal power generation in which power generation by the two or more cells is normal and determine that output limitation is not necessary and determine, when the total value is a third voltage value higher than the first voltage value but lower than the second voltage value, the normal power generation if a cathode gas flow rate is less than a predetermined value and determine that output limitation is not necessary or the abnormal power generation if the cathode gas flow rate is not less than the predetermined value and perform output limitation such that generated power in the fuel cell does not exceed an upper limit value. an acquirer configured to acquire a total value of cell voltages of two or more cells included in a fuel cell; and a determiner configured to: determine, when the total value is a first voltage value, abnormal power generation in which power generation by at least a part of the two or more cells is abnormal and perform output limitation such that generated power in the fuel cell does not exceed an upper limit value, determine, when the total value is a second voltage value higher than the first voltage value, normal power generation in which power generation by the two or more cells is normal and determine that output limitation is not necessary and determine, when the total value is a third voltage value higher than the first voltage value but lower than the second voltage value, the normal power generation if a cathode gas flow rate is less than a predetermined value and determine that output limitation is not necessary or the abnormal power generation if the cathode gas flow rate is not less than the predetermined value and perform output limitation such that generated power in the fuel cell does not exceed an upper limit value. determine, when the total value is a first voltage value, abnormal power generation in which power generation by at least a part of the two or more cells is abnormal and perform output limitation such that generated power in the fuel cell does not exceed an upper limit value, determine, when the total value is a second voltage value higher than the first voltage value, normal power generation in which power generation by the two or more cells is normal and determine that output limitation is not necessary and determine, when the total value is a third voltage value higher than the first voltage value but lower than the second voltage value, the normal power generation if a cathode gas flow rate is less than a predetermined value and determine that output limitation is not necessary or the abnormal power generation if the cathode gas flow rate is not less than the predetermined value and perform output limitation such that generated power in the fuel cell does not exceed an upper limit value.