AbstractIn the present paper the authors described laboratory fermentors used in the Antibiotics Research Institute since 1958 for research concerning the technology of the biosynthesis of antibiotics and amino acids and other aerobic fermentations. The lids of the fermentors are made from stainless steel, the vessels are made from glass. The fermentors are placed, always four each, in eight water baths with automatic temperature regulation within a range of ±0.5°C. Details regarding construction, auxiliary equipment, and working procedures used for the sterilization of fermentors and media, inoculation, injection of additives, and defoaming are given. The set‐up for one‐stage and multi‐stage, batch and continuous cultivation are discussed.