PURPOSE: To prevent a conductor and a conveyer from coming into contact with each other while reducing the drying and baking frequencies by a method wherein a thick film dried paste is provided on a conductor side coming into contact with a conveyer to be baked not to come into contact with the conveyer.

CONSTITUTION: A conductor 2 is provided on an alumina substrate 1 by means of heating and drying a printed paste likewise another conductor 4 on the backside. A printed substrate is forwarded into a tunnel furnace by means of net-type belt 5 with the surface and backside heated by infrared beams. A hole 3 is made for connecting both side conductors with each other. The substrate coming out of the furnace is cooled down to room temperature and reversed to place both ends upon the conductor 2 for printing paste on the formed surface of the conductor 2 further heating and drying the paste to produce resistors 6a, 6b for baking. The surface coming into contact with the belt 5 in case of baking the conductor does not come into contact with the belt 5 in case of baking the resistor 6 with any incompletely baked part baked completely at this time. Through these procedures, the electric properties of conductors may be stabilized producing both side thick film circuit at less baking frequency and manufacturing space.