PURPOSE: To provide an extrusion machine in which a combined die is used but for which the enlargement of the die and the increase of necessary extruding force or the like is unnecessitated even in the case of extruding a large diameter extruded material and further to provide the extrusion method using the extrusion machine.

CONSTITUTION: This machine is provided with the combined die 2 which is composed by the combination of a female die 3 and male die 4 and a mandrel bar 9 which is arranged in the state of passing through the inside of a container 1 in the axial direction. A through-hole 41a for the mandrel bar which penetrates the male die 4 in the axial direction is formed and the mandrel bar 9 is inserted into the through-hole for the mandrel bar, so a pressure receiving area on the rear end face of the male die is decreased by the amount equivalent to the cross-sectional area of the mandrel bar. Desirably, it is batter to execute extrusion by advancing/driving the mandrel bar 9 together with a stem 8 in the extruding direction and the frictional force between the mandrel bar and a billet is decreased.