PURPOSE: To strongly press-fix the extruding material which is passed through a 2nd forming clearance to the extruding material which is passed through a 1st forming clearance by having the 1st and 2nd forming clearances and opening each side opening part of the 2nd forming clearance and material pool in the 1st forming clearance.

CONSTITUTION: The 1st annular forming clearance 21 is formed between a male bearing part 20 and the hole part 13 of a female bearing. In the tip part of a forming projecting-part 19, the 2nd forming clearance 23 for forming a partition which is held between internal bearing parts 22, 22 which are forwardly opened in a slit shape is formed. The extruding material which goes to the side opening part of the 2nd forming clearance is press-fixed to the extruding material which is passed through the 1st forming clearance 21. While advancing motion of peripheral systems 7 to peripheral port hole 17 of a die 5 is continued, when advancing motion of the center system 7 in accordance with the material conducting hole 25 of a core 15 is stopped, formed products without partition are extruded.