A fuel cell system, includes: a fuel cell stack that is formed by stacking fuel cells for causing electrochemical reaction of a fuel gas and an oxidizing gas; a fuel gas supply system that is configured to supply the fuel gas to the fuel cell stack from a supply source of the fuel gas; a fuel gas recirculating system that is configured to resupply to the fuel cell stack the fuel gas discharged from the fuel cell stack; and a piping member is configured to connect a junction between the fuel gas supply system and the fuel gas recirculating system with the supply source, the piping member having a bent portion that is curved such that a supply direction of the fuel gas from the supply source is reverse to a flowing direction of the fuel gas toward the junction.