PURPOSE: To obtain a die for extrusion processing which is easily manufactured with high precision to be economical, which is remarkably low in extruding pressure and thereby eliminating the generation of deflection or crack due to the impact and the like at the start of extrusion, and which is capable of keeping the high dimensional precision at the time of its manufacture for a long period providing a long service life.

CONSTITUTION: The die is provided with a male die 31, which is nearly a square plate shape in its appearance with a projecting part 34 formed in the center of one end face 32 and with a plate-shaped fitting part 37 formed between the side faces 35 positioned on both sides of the projecting part, and a female die 41, of which an insert die 43 made of a rigid material is arranged from the main body in which a cavity 49 for forming a base material into the shape of a formed product is provided in the center of one end face 44 and in between the projecting part 34 of the main body 42, and in which on both sides of the insert die of the main body a recessed groove 51 is formed for the fitting part of the male die to engage with. In the case where the male die and the female die are integrated, the flow passage of a base material communicating with the inside of the cavity is formed between both sides 35 of the male die and the inner wall surface of the flow passage.