To provide an air-cooled fuel cell system configured to suppress thermal runaway. An air-cooled fuel cell system, wherein the air-cooled fuel cell system comprises: a fuel cell, a first temperature acquirer, a second temperature acquirer and a controller; wherein the fuel cell comprises a cooling fin made of a metal; wherein the first temperature acquirer is disposed at a position which is near a cooling air inlet of the fuel cell and which is apart from the cooling fin; wherein the second temperature acquirer is disposed to come into contact with the cooling fin; wherein the controller monitors temperatures acquired by the first and second temperature acquirers.