The thermal stability of 4-(1-adamantyl)phenol has been studied in the temperature range of 703-753 K, the components of the thermolysis reaction mixture have been identified, and the rate constants and parameters of the Arrhenius equation for the thermal degradation of the compound under study have been calculated. It has been found that of the thermal stability of 4-(1-adamantyl)phenol significantly surpasses that of 4-tert-butylphenol.