Abstract: An incubator apparatus for the brooding of any egg types with a closed housing. The brood is exposed to the same conditions in the entire apparatus. For this purpose an incubator apparatus is used which has a substantially rectangular or square housing compartmentalized by crosswalls into a brooding chamber and air-circulating chambers. The crosswalls divide the air channels into uniform and equal size cross sections. The air channels terminate below the lowermost brooding tray at the same distance from the bottom or at the right and left laterally next to the brooding tray. The air is warmed and circulated by fans which are provided with a heating source and which are arranged centrally on top or in the back equally spaced to the left and right from the air openings. A dust filter is arranged between the fan and the brooding chamber.