Heating Digester is a heating device to of the distillation process with a predetermined time and temperature. Distillation is one method in purification by separating two or more components in a liquid based on the difference in vapor pressure of each component. The heating digester is a device with its main component consisting of heating blocks in aluminum which provide or deliver very good temperature overall with a maximum working temperature of 4500C. The heating block is controlled by a microcontroller circuit and used the LM35 as a temperature sensor. The main component of the heating digester is the heater element. When the device is turned on then setting the time and temperature, then the heater will start active to produce heat which will be distributed into the digester room, in making the tool all systems are controlled by an ATMega16 microcontroller. From the research carried out at the measurement of 78 0C the results obtained were the results of the average measurement of 78 0C at 78.02 0C. The temperature deviation obtained is 0.14 0C. Then the error value is 0.19%. This value is still at the permissible threshold of +/- 1 0C. After general research, it can be concluded that the innovation of temperature and time regulation on the heating of ATMega16-based digester can be used properly and is still within the tolerance threshold value.