High temperature furnaces which in some special cases also have high pressure، are the most useful in manufacturing high resistance workpieces, the parts useful in many technologies such as aeronautic or medical. In the present study heat transfer analaysis of such furnaces is studied to be a start for future works and even manufacturing such furnaces in our country. Two shapeS of furnace is modeled in this study, the first one electric elements are designed in surroundings of furnace and in the second model they are embedded at the bottom of the furnace. Conduction heat transfer in such furnaces is negligible so two other ways of heat transfer, the convection heat transfer and the radiation heat transfer are compared. In the same fictional situation when elements are at the bottom of the furnace in comparison with elements in surroundings. Two boundary condition is assumed on the elements, constant temperature and constant heat flux. Transient mode computations is used for the both of boundary conditions.The view factor between elements and the body for the elements at the bottom of the furnace is about 0.6 and for the elements in surrounding is about 0.8. For the assumption of constant temperature on elements it is not possible to compare the convection heat transfer in two model because internal heat flux in two model is not the same and depends on the gas temperature near the elements but the radiation heat transfer in the model with elements in surroundings in the same time is about 1.7 greater than the model with the elements at the bottom of the furnace. By the other assumption, constant heat flux, it is possible to make the same internal heat flux in two model and in this situation, convection heat transfer is comparable, which in this work and the geometry assumed in this study, in he same elapsed time, just differences in temperature of the body and the pattern of heat transfer is viewed and in the same time the radiation heat transfer is about 20 percent less in the model with element at the bottom of the furnace Keyword : High temperature furnaces, Natural convection, Electronic elements, High pressure, Argon gas, Radiation