PURPOSE: To lower a necessary pressure, to decrease the heating temp. of a material, to reduce the pressure holding time and to enhance productivity at the time of forming a material consisting essentially of an Fe-base alloy by facilitating the grain boundary bonding.

CONSTITUTION: The powder of a material consisting essentially of an Fe-base alloy is cold-compressed to form a green compact P having 50-97% density ratio. The green compact P is heated, inserted into a die 1 and compacted to 85-98% density ratio by an upper punch 3 and a lower punch 2. A surplus space is demarcated in the die 1, a material flow is produced toward the surplus space to impart the degree of freedom in deformation to the green compact P, the green compact P is continuously compressed to 98-100% density ratio or to the plastic deformation region, as required, and the compact is obtained.