The results of air contamination by aerobic bacteria, coliform, and fungi are presented in Table 1. On the first and fifth sampling times, which collected samples after cleaning and disinfection in a hatchery, aerobic bacterial contamination in the operating hatchers was high, measuring over 300 cfu/63.6 cm2 except for the operating hatcher in the hatcher room-5 on the first sampling time. In addition, in the operating hatchers, coliform and fungi contamination was high, measuring over 300 cfu/63.6 cm2 on the fifth sampling time. On the second sampling time, which was conducted before cleaning and disinfection, air contamination of aerobic bacteria, coliform, and fungi in the candling-transfer room, corridor in the hatcher room-2, and chick handling room was higher than the bacterial contamination of same sampling sites on the remaining sampling times, which collected samples after cleaning and disinfection. In the egg sorting room, contamination by aerobic bacteria, coliform, and fungi was generally found to be moderate, whereas in the other sampling sites, it was minimal, measuring less than 10 cfu/63.6 cm2 for aerobic bacteria, 5 cfu/63.6 cm2 for coliform, and 2 cfu/63.6 cm2 for fungi.