To achieve a desired temperature distribution in the section of a furnace, chamber perpendiuculat to the conveying direction of materials to be peocessed by arranging electric heaters in parallel perpendicularly to the conveying direction of the materials to be processed on the ceiling part and the hearth of the furnace chamber, and arranging the electric heaters along the conveying direction of the materials to be processed on the side wall surfaces of the furnace chamber.

A continuous tunnelling electric kiln 1 comprises electric heaters 7 and 8 composed of electric resistant heat generating members by which materials P to be processed conveyed in the furnace are heated. Then, the main heat generating parts of the electric heaters 7 are arranged in parallel perpendicularly to the conveying direction of the materials P to be processed on the ceiling part 3 and the hearth 4 of the furnace chamber 2 of the kiln 1, and the heat generating parts of the electric heaters 8 are arranged along the conveying direction of the materials P to be processed on the side wall surfaces 5 and 6 of the furnace chamber 2. Thus, the space of the furnace chamber can be used as much as possible even under a strict demand for temperature distribution and a burning work can be performed without lowering a productivity.