PURPOSE: To manufacture a dense seamless pipe in which cracks are not formed by shrinkage, by dring a roughly-shaped pipe formed from the mixture of metal powder, water, a binder, a lubricant, etc., and then repeating the work of swaging-reformation and sintering with heat.

CONSTITUTION: A mixture comprising the predetermined distribution ratios of metal powder, water, a binder, a lubricant, etc. is extrusion-formed into a roughly-shaped pipe using a predetermined metal die for extrusion. After this roughly-shaped pipe is dried, it is reformed by swaging and sintered with heat at a predetermined temp. Thereafter, one more work of swaging-reformation and sintering with heat are performed. Thus, the density thereof can be increased, and the formation of cracks can be prevented.