To provide a fuel battery system capable of purifying a contamination material while generating a power.SOLUTION: A fuel battery system 2 comprises: a contamination exhaust line 6 for supplying a contamination exhaust containing a contamination material exhausted from a facility 4; and a contamination exhaust purification part 50 purifying the contamination exhaust supplied from the contamination exhaust line 6 by using a reaction heat of a fuel battery 14. The contamination material contains materials that affect organism such as bacterium, virus, or materials generating odor. The facility 4 is: a hospital being a facility where the contamination material is brought, a facility where the contamination material is grown or a facility where the contamination material is created; or an institution, a factory or an isolation facility handling the contamination material. The contamination exhaust emission purification part 50 is a power generation part 36 of the fuel battery 14, and the contamination exhaust line 6 supplies the contamination exhaust to an air electrode 38 of the power generation part 36.SELECTED DRAWING: Figure 1