To measure a flow rate of gas containing a condensed component using a mass flow meter.

A fuel cell generation system includes: a biogas generating part 13; a fuel cell power-generating part to which biogas generated by the biogas generating part 13 is supplied as a raw fuel through piping; a gas flow meter arranged in the middle of the piping and measuring a flow rate of the biogas supplied to the fuel cell power-generating part; a heating device arranged in the middle of the piping between the biogas generating part 13 and the gas flow meter and heating the biogas flowing through the piping; a first temperature detector 14 detecting a temperature of the biogas on an upstream side of the heating device; and a second temperature detector 15 detecting the temperature of the biogas heated by the heating device immediately near the gas flow meter, wherein the heating device heats the biogas so that the temperature detected by the second temperature detector 15 does not become lower than the temperature detected by the first temperature detector 14.