PURPOSE: To prevent loosening and break away of ceramic layer by dividing grooves to tube axial direction preset on a base tube at the time of dividing the ceramic coated tube produced with centrifugal thermit method into the tube axial direction.

CONSTITUTION: The base tube 1 for producing a trough is composed of a metal tube 2 as main body, in which divided grooved 4, 4 penetrating tube wall except parts in range of, for example, about 30mm from each opening end at the both ends 3, 3 to the tube axial direction are formed with means of gas cutting, etc., to the tube axial direction. Then, in the inner face of the tube 2, the sectional members 5a, 5a; 5b, 5b are stuck with means of welding, etc., at each facing side edge in the opening part of the each groove 4. Successively, this base tube 1 is rotated at low speed and the thermit agent is sprayed in the inner face thereof and the thermit agent layer 6 is formed to each part of the inner face of the base tube 1 sectioned with the members 5. After that, ignition is executed to the layer 6 under high speed rotation and the ceramic coated tube 9 forming generated ceramic layer 8 through generated metal layer 7 is obtd, and the both sides 3a having no grooves 4 are cut off and divided.