A rack apparatus for managing laboratory animals and is easy to clean includes plurality of animal cages (1) stored at intervals in a storage space (16) on a shelf plate (15) supported by frame structure (13). The rear of the storage space (16) is closed by a back plate (12b), the exhaust box (19) is installed at the top of the rear side, and a cage top cover (23) is installed at the top of the front side. A back stay (25) is demountably attached to the back plate (12b), a movement-restricting bar (27) is attached to the back stay (25), and spacers (29), which maintain intervals between the animal cages (1), are demountably attached to the back stay (25). The spacers (29) are selectively installed by mounting to/dismounting from the back stay (25) to maintain planned storage positions corresponding to sizes of the cages (1) in the width direction.
