The construction of an automated adiabatic calorimeter for heat capacity measurement ofsolids in the temperature range of 25- 90K is described in detail. The sample vessel of thecalorimeter has thin radial vanes which make no contact with its inner wall and are distrib-uted evenly, thus greatly improving the internal thermal equilibration of the vessel. Theprecision of temperature control for the adiabatic shields and electrical leads of the calori-metric system are heightened to a great extent by using the high precision ACD- 79 modeladiabatic controller specially developed by us for this purpose. Measurements of the heatcapacities of high purity α-Al_2O_3, one of the internationally-accepted standard referencematerials, agree with those of the National Bureau of Standards (NBS), USA within ±0.3%,demonstrating the reliability of this apparatus. The construction of an automated adiabatic calorimeter for heat capacity measurement of solids in the temperature range of 25-90 K is described in detail. The sample vessel of the calorimeter has thin radial vanes which make no contact with its inner wall and are distrib- uted evenly, thus greatly improving the internal thermal equilibration of the vessel. Theprecision of temperature control for the adiabatic shields and electrical leads of the calori-metric system are heightened to a great extent by using the high precision ACD- 79 modeladiabatic controller designated developed by us for this purpose . Measurements of the heat capacity of high purity α-Al 2 O 3, one of the internationally-accepted standard reference materials, agree with those of the National Bureau of Standards (NBS), USA within ± 0.3% demonstrating the reliability of this apparatus.