A novel microisolation container for laboratory animals or other species includes a rectangular, transparent base containing an intake port at the lower front end and a detachable top sealingly attached to the base which contains an exhaust port in the end opposite the intake port. The intake and exhaust ports are preferably covered with a filter membrane which excludes airborne contaminants. The interior of the top is contoured to provide a domed sloping ceiling for the container, the lower portion being adjacent the intake or front end of the container and the upper portion being adjacent the exhaust or rear end. Preferred embodiments include a feeder assembly which is supported by perforated supports which serve as shelter for the animals. The front and rear ports, the contoured ceiling and the feeder design aid in the laminar flow of air through the cage. A perforated floor, absorbent insert and disposable waste bag can be included in the base of the cage.