Patent ID: 7981558

Claim:
A fuel cell system, comprising: a fuel cell; a supply flow passage for flowing a fuel gas supplied from a fuel supply source to the fuel cell; a variable gas supply device which regulates the state of the gas on an upstream side of the supply flow passage to supply the gas to a downstream side; a discharge flow passage which flows a fuel off gas discharged from the fuel cell; a discharge valve which discharges the gas from the discharge flow passage to an exterior; and a control device configured to delay the timing of closing the discharge valve when the discharge amount of the gas exceeds a predetermined target discharge amount, the discharge amount of the gas being calculated while the discharge valve is opened and when the variable gas supply device starts to supply the gas, the control device being configured to close the discharge valve simultaneously with the stop of the gas supply from the variable gas supply device, in a case where the discharge amount of the gas calculated while the discharge valve is opened and when the variable gas supply device starts to supply the gas exceeds the target discharge amount, the gas supply being the supply of the fuel gas corresponding to a pressure decrease on the downstream side of the variable gas supply device due to the discharge of the gas from the discharge valve.