Abstract: The present invention relates to a method of controlling an output variable of a process having long dead times and delay times, for example for controlling the interior temperature of an absorber refrigerator, and also relates to an apparatus for carrying out such a method. The output variable of the process, such as the interior temperature, is sampled and compared with a desired value in order to determine a desired value deviation. In dependence on the determined desired value deviation, a manipulated variable, such as the power supplied to the absorber, is calculated in such a manner that the output variable of the process is brought near to the desired value. After the lapse of a waiting time, a value of the manipulated variable is newly determined. During the waiting time, the manipulated variable is not altered. The waiting time is calculated on the basis of the difference between the value of the manipulated variable and an earlier value of the manipulated variable.