To provide a fuel cell device which can efficiently purify harmful components in exhaust gas generated from power generation by a fuel cell during a period from startup to initial power generation.

A fuel cell device 1 comprises a fuel cell 2, a heat exchanger 4 which recovers heat from exhaust gas generated from power generation by the fuel cell 2, and a purifying device 3 which includes a combustion catalyst necessary to purify harmful components in the exhaust gas. Given that the purifying device 3 has a heating device which heats the combustion catalyst with exhaust gas generated from power generation by the fuel cell 2 and ejected into the heat exchanger 4 after being internally circulated, activity of the combustion catalyst can be improved and, hence, the exhaust gas generated from power generation by the fuel cell 2 during a period from startup to initial power generation can be efficiently purified.