The structure and principle of operation of a heating unit intended for the thermal and radiation-thermal treatment of luminescence ionizing-radiation detectors aimed at modifying their dosimetric characteristics are described. The unit provides for linear heating of detectors in the range of 50–700°C at a given rate from 1 to 15°C/s, as well as for isothermal exposure of detectors. A description of unit operation is given as well as the results of trial tests that prove a high accuracy in reproducing the temperature and heating rate, acceptable for problems being solved.