To provide a method for conducting hygiene maintenance, including deodorization, in a chicken farm, capable of especially preventing a chicken from being infected with infectious pathogenic bacteria and viruses, by sterilizing or inactivating the infectious pathogenic bacteria and viruses attached to a cuticle of a chicken body, without causing expression of hazardousness to the chicken body, capable of decreasing an incidence rate and an accident rate (mortality rate) of the chicken, and therefore capable of increasing production efficiency of a chicken farmer, and to provide a chicken raising installation.

This method comprises spraying the inside of the chicken raising installation with high-concentration ozone water having a concentration of ≥0.8 ppm and generally of ≤30 ppm by shower equipment located in the chicken raising installation. The ozone water is directly sprayed on a floor surface of a chicken house, a floor covering material, a passage, a waterer, or the chicken body itself. Further, the ozone water is used for washing the hand of a chicken raising operator, footwear in a state of being worn by the chicken raising operator, and a vehicle going into the chicken raising installation. Thus, the hygiene maintenance of the chicken raising installation is conducted by sterilizing or inactivating the infectious pathogenic bacteria and viruses.