PURPOSE: To obtain extruded shapes with excellent strength by combining the female die of a port hole dies and the male die of the same dies, arranging a disklike baffle component and setting bridge parts with which the introducing holes are mutually separated in the position where the introducing holes of the male die for material to be formed are intersected.

CONSTITUTION: When a billet is extruded with this extrusion die, the material to be formed which is branched with the bridge parts 14 of the baffle component 3 is caused to join in the introducing holes 10 of the male die 2 for material to be formed. The material to be formed which s joined in each introducing hole 10 of the male die 2 for material to be formed is caused to flow into a inflow recessed part for material to be formed of the female die 1 and is joined there. Expected hollow shapes extruded are obtained by extruding the material from the forming clearance which is formed between the opening part for forming of the female die 1 and the projecting part of the male die 2 for forming. By this way, because the material to be formed is meandered by repeating branching and joining when the material is passed through each die, the joining surface is largely deformed and strength of the joining part can be improved.