PURPOSE: To efficiently and compactly perform removal of phosphoric acid in exhaust gas, recovery of waste heat and recycling of condensed water by integrating a high temperature portion heat exchanger, a phosphoric acid recycling pallet, a low tempera ture portion heat exchanger and a condensed water recycling tank with one another.

CONSTITUTION: When the exhaust gas of a fuel cell main body 11 is allowed to flow into a high temperature portion heat exchanger 21, it is cooled by cooling water to a temperature range where phosphoric acid is deposited, and the phosphoric acid deposited is collected by a phosphoric acid recycling pallet 22. The exhaust gas flowing into a low temperature portion heat exchanger 23 is cooled to a temperature range where generated steam condenses, and the condensed water is collected into a recycling tank 26. The cooling water is allowed to flow out into an outlet line 28b from an inlet line 28a through the heat exchangers 23, 21 and a series of heat transfer pipes 27. Since the exchangers 21, 23 and the recycling pallet 22 and tank 26 can be integrated with one another, removal of phosphoric acid, recovery of waste heat and recycling of condensed water are efficiently performed and the device can be made compact as a whole.