FUEL CELL SYSTEM

PROBLEM TO BE SOLVED: To solve the problem in which: a fuel cell system 1 cannot effectively perform an operation avoiding cutoff of a gas meter in a case of power failure.SOLUTION: A fuel cell system 1 comprises a fuel cell unit 2 and a hot-water storage unit 3. The hot-water storage unit 3 includes a first controller which performs an operation avoiding cutoff in which combustion amount of combustible gas in a combustor 6 is varied to avoid the cutoff of a microcomputer meter detecting flow rate of the combustible gas, and measures the elapsed time during which variation of gas consumption required for avoiding the cutoff of the microcomputer meter does not happen. The fuel cell unit 2 includes a second controller 12 which sends information notifying the necessity of performing the operation avoiding cutoff to the first controller 4 when power supply from the commercial power supply 15 is started and when the fuel cell unit 2 is activated by electric power supplied from the fuel cell stack 10.