PURPOSE: To effectively manufacture the cylindrical body with the flange for using the bush, etc., of the power shovel with the assembling system without machining.

CONSTITUTION: A cylindrical member 10 and a flange like member 11 are piled by putting an insert material between their matuing surfaces. In the state restricting the piled body 13 to the axial direction, the neighborhood of the putting surface of put body 13 is heated with high frequency of heating coils 29-32 from the inner surface side and the outer surface side. By means of this heating, the insert material between the matuing surfaces is molten, and together the joining load is enough applied on the matuing surface with the reacting force of the piled body 13 toward the axial center direction following to the thermal expansion, and the cylindrical member 10 and the flange like member 11 are joined with diffusion joining.