PURPOSE: To find out a friction coefficient μ(= F/P) by measuring force P vertical to the wall face of a movable die which is received from powder in the die and frictional force F in the wall face in a pressing direction by a cell fixed to the die.

CONSTITUTION: At first, press stress (f) is applied from the rear face of the movable die 2 to contact faces 7, 7' and 8, 8' between the die 2 and a die body 1. In said state, the face pressure P is set up to '0'. When operation conditions are controlled so that the friction coefficient found out by said procedure and a stress-strain relational curve found out by a known method are always constant, molded product having the same density distribution can be obtained. When temperature distribution for sintering is controlled to a constant state, products having the same shape and size can be obtained. In said procedure, the friction coefficient and stree-strain relation can easily be related to various process dominant factors such as the material characteristic values of powder and die conditions.