It was established that A. laidlawii cell viability in the stationary phase of culture development decreases according to the Gompertz law. It was shown that the "stationary" ageing of A. laidlawii cells is accompanied by the lower intensity of phosphorus-containing compounds biosynthesis, decreased rate of membrane proteins synthesis and degradation and also by accumulation of DNA single-strand breaks. The biochemical changes found in ageing A. laidlawii cells are similar to ageing manifestations of resting eucaryotic cells. According to the authors opinion, the received data show that the A. laidlawii cell culture may be used as an object for investigation of the cell ageing mechanisms.