Abstract: A fuel cell power generation device prevents contamination of the cooling water of the fuel cell and maintains the pressure of the cooling water tank at the atmospheric pressure. The fuel cell power generation device includes a communicating pipe that connects the cooling water tank and the recovered water tank. The communicating pipe has a first blocking part and an open-to-atmosphere part located nearer to the cooling water tank than the first blocking part. An open-to-atmosphere device is located at a position higher than the first blocking part and couples the open-to-atmosphere part of the communicating pipe to atmospheric pressure.