Abstract: The apparatus which includes a cell culture chamber enables cell biological experiments with botanical, zoological or homological cells to be carried out. The apparatus comprises a pump housing and a cell culture block with a cell culture chamber therein in which the cell culture medium or nutrient can be automatically and continually exchanged by the action of an osmotic fluid pump connected to the chamber. The osmotic fluid pump is activated by a fluid filled into a cavity in the pump housing. The osmotic fluid pump forces its pre-charged contents, i.e. the cell culture medium or nutrient, through an inlet passage into the cell culture chamber. The exhausted or expanded cell culture medium or nutrient can drain or exhaust through an outlet passage into the cavity of the pump housing. This ensures that no excess pressures arise in the system. The apparatus is especially well-suited for carrying out or implementing biological experiments under zero gravity conditions such as prevail in spaceships.