A target electric power operating part (2) operates a target electric power of a fuel cell. A running target point operating part (3) operates targets of both pressure of gas and mass flow rate of gas. A running point controlling part (4) controls a running point of the fuel cell. A running state detecting part (5) detects a running state of the fuel cell. An output power limit operating part (6) operates a limit of the output power produced by the fuel cell, based on the running state e.g., pressure of the gas detected in the running state detecting part (5). A commanded output power operating part (7) operates a commanded output power, the commanded output power being defined as a minimum value between an output from the output power limit operating part (6) and an output from the target electric power operating part (2).