EN
In the paper the thermal deactivation of chitin deacetylase separated from Absidia orchidis vel coerulea was investigated. Experiments were carried out at a temperature of 50ºC up to 24 hours. Three mechanisms of deactivation were tested: irreversible first-order, reversible firstorder, and three-parameters phenomenological model. It was found that the last one gave the best approximation of the deactivation process. The parameters of the model were evaluated and the model was also confirmed by independent experiments.