Biogas is a clean and renewable energy generated from organic digestion under anaerobic condition. The anaerobic process is held inside a biogas digester. The production of biogas in a biogas digester might be affected by the temperature degree and humidity of the digester. This research focused on building a real-time instrument system for observing the temperature and humidity in a biogas digester. The system was mainly consisted of biogas digester acquisition system and the observation of its application system. The temperature and humidity data captured from the biogas digester were shown in the form of tables and charts through the observation system. In general, it can be said that the real-time instrument system built in this research had an ability to observe and measure the temperature and humidity in biogas digester. Thus, the real-time instrument system could be utilized as a viable and easy alternative instrument for the monitoring/observation of anaerobic digestion in biogas production.