Disclosed is a fuel cell system including a fuel cell, a pipe forming a fuel supply passage through which a fuel gas supplied from a fuel supply source flows to the fuel cell, an on/off valve which regulates a gas state on the upstream side of the fuel supply passage to supply the gas to the downstream side, and control means for controlling the opening/closing operation of the on/off valve. The control means sets a required time from the opening time of the on/off valve to the closing time of the valve so that the vibration level of the pipe on the upstream side of the on/off valve is a predetermined reference level or less.