The ceramic products processing requires a high consumption of energy. Through the drying and firing stages, the molded product is subjected to high temperatures in a kiln, to obtain the product with required levels of rigidity and resistance. This energy consumption must be evaluated to improve the energy efficiency of the process. This work presents the fundamentals of ceramic materials processing and perform a thermal analysis in an intermittent ceramic kiln. This analysis is based on heat transfer measurements, that occur in the kiln during the ceramic production stages, and effects of the thermal insulation thickness on the heat transfer between the kiln and the environment. The results showed that a considerable amount of energy is used to heat the kiln surfaces, that the greatest heat loss occurs by radiation of the kiln walls and that the use of thermal insulation provides considerable reduction in this heat loss, as well as the reduction in kiln external temperature, which minimize thermal discomfort and work accident risks.